Align your car at home?

[Kern Dog]

Heck yeah!
I've grown tired of paying the man to get my car aligned and then not knowing for sure that I got the numbers that I paid for. I'm going to start doing it myself. The start up costs are about the same as you'd pay for ONE professional alignment so why not give it a try?
You don't need an alignment rack.
Guys with 4wd trucks have been aligning theirs with string lines for years. Of course, solid axle trucks have fixed caster and camber angles so all they adjust is the toe....
The Mopar suspension isn't hard to figure out so it is disappointing to repeatedly hear that one of our Mopar brothers took their car to some big-chain repair facility, paid $180 and the car steers as bad after as it did before.
I started this thread to better highlight my own experiences in learning how to do this. Please feel free to add your own observations and experiences. I will surely make a few mistakes during the learning process as I am not trained in this stuff. Like most of you, I'm just a guy that loves these cars and loves to tinker with them.

I recently watched this video:

https://www.youtube.com/watch?v=yAqZyr7JzCw&t=15s&ab_channel=Junkerup%23chrisbirdsong

DC,com member Chris Birdsong recorded the video of how he does alignments using some readily available tools. He doesn't post here much anymore but he is a great asset to the hobby. You can learn a lot from this guy.
The first step is to jack the car up and set it on the turning plates. You can get really fancy with these but all you really need is a way for the tires to steer with minimal resistance. You don't want the suspension or steering in a bind because that will affect the readings. In the video, Chris shows how he made steering plates by taking 2 steel sheet metal segments and after putting chassis grease in between, the two plates will slide any direction you want and stay stuck to each other. See pix:



 

These were simple 14 gauge galvanized steel panels 14" x 14".



I just smeared axle grease on the face of one, then laid another sheet over it.



Now you jack up the car and slip the steel sandwiches under the tires.





The second thing to do is to establish the desired ride height. A trained Mopar mechanic will refer to the manual where it instructs you to measure two parts on the chassis, do some math and come up with a number.
No thanks....
Just about everyone else that I've ever met does it the same way that I have done it: Measure from the pavement to the top of the wheel opening. Once you lower the car so the tires are on the turning plates, you'll see how the top section slips sideways off of the bottom:

 

Cost of metal plates: $44.

[Kern Dog]

The same thing happens on the other side.


You see, usually when you have a Mopar up off the ground and then set it down, the track/width of the suspension isn't established because it is in a bind. You usually have to roll the car forward and back a few feet to let it settle. These grease plate sandwiches/turning plates allow the top sheet to slid over and the suspension settles. See what they do when you turn the wheel:







Now you bounce the front end down a few times and it will settle. You can crank on the torsion bar bolt to raise or lower the car to where you want it. Be sure to bounce the car up and down a few times after each adjustment to get it to settle.

The next step is to establish the caster and camber angles. For that, I'm going to use this:



There are many variations of this tool. Some are battery powered but the one I bought uses a bubble like a level. No batteries to replace and the bubble is basic technology that has worked for 200+ years.  I ordered this one through Amazon.com but it hasn't arrived yet.

To establish Toe,  I ordered these:



Now these are designed to bridge past the tires so you can hook a tape measure over the edges and measure the distance in front of the tire and behind it. These haven't arrived yet either.

Years ago, Mopar Muscle magazine printed an article where a guy mapped the alignment curves of two popular disc brake knuckle/spindles that we use in our cars. One was the 1973-1976 A body version, the second was the much more plentiful "B" spindle that was used from around 1973 to 1989. Here are the maps he charted starting with the A body unit:



The numbers he recorded really surprised me. I couldn't believe how much the alignment really does change in such a short amount of wheel travel. Look at the changes from zero (standard ride height) to 2 1/4" dive and 2 1/4" rise. I was shocked at how the height dramatically changed the caster.

Now look at the later "B" knuckle/spindle:



With the A unit, you gain 3.7 degrees of caster at dive. The B unit you gain 3.4 degrees. 
 I recently raised the car 1 inch. Doing so cost me about 1.8 degrees of caster. I am still amazed at that. It seems impossible that so much changes in such little difference in ride height.

Metal plates:   $44
Caster/Camber gauge:  $136 plus shipping.
Toe plates: $34 plus shipping.
Total so far, $214 plus whatever the shipping charges may be, if any.

[Kern Dog]

What started this project is that I recently raised the red car 1 inch to quit scraping over speed bumps. The suspension is firm so it isn't bottoming out due to saggy bars and springs.

These tires are 200 treadwear and very sticky.



In February last year I had it aligned at a trusted shop. I told them I wanted .75 degrees of negative camber, 1/8" toe in and as much caster as they could get. Since these were not "book specs", I had to pay for the alignment by the hour to the tune of $160. Not a terrible price if it is right though, right?
The man told me that they got 5 degrees of caster on the left and 5.5 on the right.
How do you know if it is right if you don't have a way to check it yourself? Are you a good enough driver to know just by feel?
I'm a decent driver but not that good.

[Kern Dog]

I just ordered these:



I didn't think that I'd need them since the alignment shop was able to get 4.5 degrees of caster years ago and 5.0 + degrees last time but since I doubt their claims and don't trust them, I went ahead and ordered these tubular arms.
I plan to do a series of mock ups and tests to see what numbers can be achieved with stock arms with stock bushings, stock arms with the offset bushings and these tubular ones with 3 degrees more caster built into them.

[Kern Dog]

This arrived last night.














The QA 1 control arms just arrived moments ago.   

   

[Kern Dog]

The QA 1 UCAs just got here.















There was nothing in the instructions about what grease to use. Usually. urethane bushings need a specific lubricant to avoid squeaks. I called their tech line...The man said to just use the same quality lubricant on the bushings as I would for the ball joints.       

[Kern Dog]

For years, I've been under the impression that the alignment specs that I asked for were what I received.
It turns out, that is not the case.
This pisses me off. The alignment guy gets a request and puts the car on the rack and should do his job.
Mine didn't.
About 10 years ago, I replaced the lower control arm bushings and a tie rod end and had it aligned. The man said they were able to get 4 1/4 degrees of caster, .75 degrees (3/4 degree) of negative camber and 1/8" toe in. Last year after having the engine, K member and all the front suspension out of the car, I had it aligned again. This time I had shorter rear tires and less rake to the car. The man claimed to get 5.5 degrees of caster right and 5 degrees left and .75 degree of negative camber.
Today I measured it and it isn't even close.
Left side camber is positive instead of negative.



Left side caster:



Right side camber isn't bad but isn't where it is supposed to be. That is about 5/8 a degree, not 3/4.



The caster is way off too. There is about 3 1/4 degree, not 5.5.



Backing up....
The left lower ball joint has some play to it so I can't blame the shop entirely. Still, 3 1/8 degrees of caster is close to the right side reading but nowhere near 5 degrees. What makes that really annoying is that there is still room to adjust the UCA cam bolts. They are now maxxed out. The guy did a lazy job and tried to pass it off thinking that I'd not find out. This is shit work.
I'm going to replace both lower ball joints and recheck the numbers. 

 

[Kern Dog]

The ball joints....







I replaced the lower ball joint on the left side and checked the alignment again. It restored the negative camber slightly. It measured 3/4 degree as it should have. It went backwards on camber though. I had about 3 degrees yesterday, today it was 2 1/2.
When I assemble a Mopar front suspension, I set the alignment cam bolts the same way in every car. I turn the front bolt to push the arm OUT. For the rear, I turn the bolt to push the arm IN toward the engine. This gives the most caster possible. This is just a baseline setting that the alignment guy starts with.
I did this with this car and it was set that way when I took it to the shop in February 2023.
To recap, I told the counter man what I wanted...3/4 or .75 degrees of negative camber. 1/8" toe IN and as much caster as they could get. After the man was done, the counter man said he got the camber and tow where I wanted and 5.5 degrees caster left, 5.0 on the right!



Looking at the cam bolts, both were in the middle of the range of adjustment. I knew just by looking at the cam bolts that the car wasn't aligned to the numbers the man said.
I went ahead and turned the cam bolts the way I always do and checked the readings.
Can you believe....I actually got 5.5 degrees of caster and 7/8 degree of negative camber!
Okay, what happened then? Did the alignment cam bolts loosen and move around? I don't think so.
I looked at the right side. The front cam bolt was close to the outside as I had put it but the rear was in the middle. The readings were 5/8 degrees of Negative camber and 3 1/4 degrees of caster.  I decided to move the cam bolts around to see what numbers I could get.
I adjusted the cam bolts like I always do, front OUT, rear IN. This gave 5 degrees of caster but it lost camber. It was now at 1/8th degree of negative camber. To get more negative camber, I'd have to move the rear cam out or the front cam in and either one would take away caster.
Here is what I think happened.
The alignment guy started with the left side and saw that he was able to get great numbers. Then, the right side wouldn't allow it without changing parts so he compromised. It looks like he set it so I got some of both caster and camber.  The problem is, the guy should have told me! I'm a grown man, I can take it. Lying to a customer because you think they'll never know is a bullshit way to treat customers.
I could shim the lower ball joint on the right side to gain negative camber while maintaining caster. That is still an option,

[Kern Dog]

Next up is the UCA swap on the left side. The control arms on this car are stock and original to this car. I put Moog offset bushings in the UCAs some 10+ years ago.





The reason for switching to the tubular UCAs is to get the additional 3 degrees of caster that they offer over stock arms. I suspect that the offset bushings gave about 2 degrees but until I mock them up and compare them to stock arms, I'm not sure.
The QA 1 arms felt heavy but I wasn't sure how they compared to stock....





Wow....the stock ones are a half pound lighter.
The tubular arms have several advantages. The poly bushings at the frame end are robust and should last a lot longer than the rubber offset bushings since they have that thin edge due to the offset:

 

 

[Kern Dog]

The QA 1 UCAs are tubular in design which does allow more room to get a wrench in there to adjust the cam bolts. There are Zerk fittings for the bushings too.



They have a flat plate for the bumpstop too.

[Kern Dog]

The right side readings were 5/8 degrees of Negative camber and 3 1/4 degrees of caster.  I decided to move the cam bolts around to see what numbers I could get.
I adjusted the cam bolts like I always do, front OUT, rear IN. This gave 5 degrees of caster but it lost camber. It was now at 1/8th degree of negative camber. To get more negative camber, I'd have to move the rear cam out or the front cam in and either one would take away caster.

In situations where you can get the caster but the camber is at zero, positive or barely into the negative, there is an easy fix.



Placing a spacer between the ball joint and knuckle tilts the knuckle out at the bottom, resulting in negative camber. The amount of camber depends on the thickness of the spacer. The ones in the picture are supposed to result in 2 degrees. Now, I don't want nor need 2 degrees of negative camber so I'm going to look for something thinner. The washers in the picture look thicker than 1/8", possibly 3/16". I have some washers here that are .09 thick and .10. I'll experiment with the thinner ones first and see what numbers I can get.

[Kern Dog]

The right side lower ball joint didn't seem bad but since the left one was worn, I replaced both. Once it was out, I could feel that it moved around a bit too easy so it was good that I changed it.



To gain some negative camber on the right, I used .090 spacer washers in between the knuckle and the lower ball joint like these:



I replaced the right UCA too.





I went to work checking numbers. With the front cam OUT and the rear cam IN, I got 2 1/2 degrees of Negative camber and over 8 1/2 degrees of caster! Too much!
I dialed it back to this:



I may take the camber to a full degree and see where the caster ends up. If I get 1.0 N camber and 7 1/2 degrees of caster, I might leave it there. The left side.....



I think I could get to 1.0 neg camber and 7 1/2 degrees caster just by adjusting the front cam bolt in a little.
Stay tuned!

 

 

[Kern Dog]

This made me smile....

[Kern Dog]

Good news.
I adjusted both sides to 1.0 degree of negative camber and 8 degrees of positive caster. I wasn't aiming that high but that is where each side landed when I aimed for the camber. I set the toe and drove it.
Wow...no wandering, no squeal and the steering wheel really wants to return to center after turns. It has over double the caster angle it had before so this is great!

[armor64]

Thanks so much for this write up KD.
After raising my car up in the nose this spring, I've noticed its harder to turn 1 way vs the other and i guess feels like its slightly pulling. Most of the shops nearby dont work on old stuff anymore, and my buddy at the shop who did my safety/alignment back in the day is no longer working in the industry. he did his best with my stock arms / stock style bushings, but couldnt get it dial in well with the non-offset bushings, but made it drive well enough for me at the time.

I may have to look into getting a setup like this, plus either the \/ bushings or qa1 style arms as well now that everything else on the car works so well LOL.

[bakerhillpins]

Nice write-up!    This is definitely something I'll keep in mind.

Now I just need a concrete floor and the garage to go with it.

[Kern Dog]

Thanks so much for this write up KD.
After raising my car up in the nose this spring, I've noticed its harder to turn 1 way vs the other and i guess feels like its slightly pulling. Most of the shops nearby dont work on old stuff anymore, and my buddy at the shop who did my safety/alignment back in the day is no longer working in the industry. he did his best with my stock arms / stock style bushings, but couldnt get it dial in well with the non-offset bushings, but made it drive well enough for me at the time.

I may have to look into getting a setup like this, plus either the \/ bushings or qa1 style arms as well now that everything else on the car works so well LOL.

The story I keep hearing is that most alignment guys nowadays are trained mostly on setting TOE since most cars don't have adjustments for caster and camber. Finding a guy that is qualified to rotate cam bolts, swap around shims and adjust torsion bars seems to be getting harder to do. It sounds a bit tin foil hat but how about carburetors and points ignitions? The new mechanics are not trained on this stuff either. Iy may be up to US to learn more to keep our cars going.

[Kern Dog]

Aligning the red car (Ginger) was done by resting the alignment gauge against the flange on the front wheels as shown here:





Because the wheel is aluminum, the magnetic base of the gauge was of no value. Each measurement was done by physically holding the gauge against the wheel.
I knew that I was going to have to find another way since cars with steel wheels have the wheel hub inboard of the brake hub and there was no wheel edge to rest against. I saw a guy post about an adapter he made that attaches to the spindle threads so I made my own.








 
 

[Kern Dog]

If I had a lathe or a mill, I'd be able to make stuff like this look a lot nicer but this will work.
 Jigsaw has steel wheels so I figured this adapter can just screw onto the spindle threads and rest against the edge of the hub.





The outer diameter of the adapter is too big to fit. The lug nuts are in the way.



If I attached the adapter with the nut on the inside....



The welded nut butts into the bearing nut. The plate doesn't rest on the hub flange but it is all solidly mounted.



I checked camber with the adapter this way then with the gauge just directly on the hub. I got the same reading so it looks like mounting to just the spindle itself is plenty accurate.


 

 

 

[Kern Dog]

To get the camber reading, the tires are pointed straight ahead.
To get caster, it is a bit different. For the LEFT wheel. you turn the steering to the LEFT 20 degrees. Since my turning plates are home made stuff, I don't have a degree scale on them. the trick is in the gauge itself. The end with the small bubble level has a gentle point to it. Each side is 20 degrees from square.



With the wheel turned LEFT, the bubble end of the gauge needs to be parallel  with the car.





Now you adjust the gauge by turning the brass knob until the bubble in the caster section moves to ZERO. This resets the gauge to get the readings correct.
Next, you turn the wheel to the right and stop at 20 degrees off center to the right.



The caster will show on the gauge now.



Holy crap....how did I get this much caster? I'm thinking that I must have put offset bushings in these UCAs back when I assembled the front end almost 4 years ago.


   

[Kern Dog]

I started thinking that it would be better if the plate on the adapter were smaller in diameter so it could fit in between the lug nuts.




This was still spindle mounted but I had this nagging feeling that it would be better if the adapter did actually rest against the hub ridge. To do this, I'd need to install it with the nut to the outside.



Yeah, it looks a bit sloppy, I'll admit. That isn't the problem. The problem is that even with it laying this way, the plate still doesn't rest against the hub because the bearing nut actually sticks out past the hub.



I had this idea....


Yes...Take TWO. This method works for those that have no welder onsite. It simply consists of another 1/4" thick plate, a few washers and nuts.





     

 

 

[Kern Dog]

The silver colored washers space the plate off the hub enough to clear the bearing nut. There wasn't a lot of threads left on the spindle but there were enough. Here are my readings:



Not much camber. How about caster?



Holy crap! Again, this seems impossible for a combination unless it has the offset bushings. These numbers are familiar though. The red car had similar numbers on the right side:



This was with the stock UCAs and offset bushings. I got more negative camber by using those spacer washers between the knuckle and lower ball joint like so:



More to come.... 

 

[Kern Dog]

I went through my notebook for the Jigsaw Charger.
I did actually use offset bushings in the upper control arms, I just forgot that I did.
This explains why I was able to get so much caster.

[Kern Dog]

It is strange though how two cars of mine, both 1970 B bodies were able to get caster numbers that few others seem to get.
Why is that?
Jigsaw has more rake than Ginger. It has a 2 inch rake where Ginger is 1 inch.
Jigsaw has a front clip from a 1970 Belvedere so it isn't even a dedicated "Charger" front end as if that matters.
I've heard from many people how they just couldn't get more than 2 degrees of caster.
I have seen first-hand that IF you want big caster numbers, you will have to accept some negative camber. Those go hand in hand. You cannot have positive camber and a high positive caster number without changing parts. You might get 3 degrees of caster and zero camber with these tubular or multi-adjustable UCAs but why? Negative camber helps with cornering grip. Embrace it. Respect it. USE it.

[Dino]

Good timing. I need to align mine after I set the ride height. I guess I need to go find some sheet metal and toe plates. Thanks for the write up!

[Kern Dog]

You are welcome.
I was impressed at how it started to make sense as I got deeper into it all. The direct relationship of caster and camber was something that I'd heard of but hadn't seen in front of me before.
Two separate cars with similar construction, similar parts and they got similar numbers.
I've read for years from guys that had trouble getting adequate caster and thought my red car was somehow rare or unusual since I've always been able to get good numbers with it. Now with the second Charger getting similar numbers, I wonder how other guys have had trouble.
A buddy texted me today...His '68 Dart has offset bushings but was aligned to 1 3/4 degrees positive caster and 1/4 degree negative camber. That car should have been able to do much better. The guy is going to bring his car over here on Monday and we will see what numbers we can get with some adjustments.

[timmycharger]

Thanks for the write up, had I seen this a few years ago I would have attempted it. Next time I have the front end apart this is what I am doing!   

[Mike DC]

 
I once measured the front suspension to figure out how far off A-arms were compared to modern alignment specs (3 degrees of caster* and 1-2 degrees of negative camber).  Like, how much different would the A-arm dimensions be if the factory engineers had designed them for modern steering/tires in the first place. 

(3 degrees of caster is still not much for a modern car.  Some have 6+ degrees.  But the old Mopar front end starts getting out of whack when you take it that far.  Bump steer, etc.)


Getting modern camber doesn't take much. The upper ball joint needs to move around 1/4" inwards (towards the engine).  It partially depends on where you have the front end ride height set.  Lowering the ride height has a side-effect of improving the camber a bit. 

But the caster is a bigger change.  The ball joint has to move back (towards the rear of the car) about half an inch.  The bushing adjustments weren't intended for changes that big.

Adding it up, IMO there's a good argument for using custom/aftermarket A-arms.   



But the offset bushings aren't bad.  They do enough to offer a practical improvement. 

IMO it makes sense to prioritize the caster gains more than the camber gains (within reason).  Modern tires are more forgiving of camber issues than old bias-plys were.  The self-centering steering (from added caster) is a more rewarding change that you feel all the time you drive the car.  The camber improvement is most noticeable in rare moments when you are cornering hard.  And modern camber is actually a drawback for hard braking. 

[Kern Dog]

The Caster angles in newer Challengers is surprising.

[Kern Dog]

Yeah, you read that right...The SRT8 cars had over a degree of negative camber and right at 9 degrees of caster.

[Mike DC]

Yeah it's a big difference. 

I don't think it would work to take the old Mopar front end that far away from zero (the original spec).  Not with only a moved upper ball joint.  The whole front end has other quirks that modern stuff doesn't.  The upper ball joints move around a lot (by design) depending on where they are in the wheel travel.  Behind the LCAs, the torsion bars pass through the ideal place for the steering linkage so that's another compromise.  Etc.     

The old Mopar engineers gave the front end zero caster because everything was still designed around manual-steering cars back then.  They needed to keep the low-speed parking effort under control.  Putting big caster into front ends is a luxury you have when there is power steering to assist in parking lots. 

[Kern Dog]

Well given that I have power steering along with the majority of others, the zero or negative caster readings the factory service manual calls for is stupid.
Mine drives great with the 8 degrees of caster. The wheel returns to center with greater authority than before, The car has always been stable at speed.

[Mike DC]

Well given that I have power steering along with the majority of others, the zero or negative caster readings the factory service manual calls for is stupid.
Mine drives great with the 8 degrees of caster. The wheel returns to center with greater authority than before, The car has always been stable at speed.

Wait, you've got 8 degrees of caster on a '70 Charger?

[Kern Dog]

Yes. I was able to get over 5 degrees with 2 separate '70 Chargers using offset bushings in stock control arms.
The QA 1 upper control arms allowed me to get 8 full degrees and the 1.0 negative camber. I was amazed too.
My picture files are too big, I'd have to find a way to resize or take new pictures with the gauge attached to the spindle.

[Mike DC]

   
How is the feel of it? Bump steer? any other unpredictability? 

How raked is the stance of the car?   

[Kern Dog]

Since the wheel arches at the front are up slightly higher than the rear, the way that I usually measure my cars is not accurate to describe rake. I measure to the top of each wheel arch. The front of the red car sits lower than the rear by one inch. If I pulled a string line across the rocker panels, I could properly assess the amount of rake. I just haven't taken it that far yet.
As it is, the front reads an inch lower at the wheel openings on the red car. There is a 2 inch difference with Jigsaw, the beater Charger.
I noticed no difference in bump steer from the driver's seat. I didn't measure it during the alignment. I'm aware that tilting the knuckle back also tilts the ball joint steering arm down (increasing bump steer) but I didn't notice a change there. It feels stable, the steering effort didn't increase.

[Mike DC]

 
Yeah, I'm surprised you got that much caster without bumpsteer issues cropping up. 

[Kern Dog]

Well, I didn't drive on any cobble stone roads yet so who knows.
I've heard of guys cold bending their ball joint steering arms to get the bump steer numbers back down. I'd need a press to do that sort of thing.

[Mike DC]

 
It's not exactly recommended in shop manuals but it's do-able.  Those arms are just forged steel.   Off-road guys bend & fabricate that kind of stuff all the time. 

The 1973-up lower control arm design is more workable for this kind of tinkering.  The steering arm is an individual piece that's not integrated with either the spindle or the ball joint. 

[Kern Dog]

Yeah, but then you'd have to drive a 73-74 model instead of a '70.

[Mike DC]

Yuk, yuk.

The later front end has grown on me over the years though.  I'm a 2nd-gen guy but there are things to like about that isolated 73-up K-frame design.  I don't see THAT MUCH extra weight, but I see a lot more room to modify things without cutting the unibody.   

[Kern Dog]

Just messing around.
I actually like the 71-74 Charger and the 73-74 Satellites. There was a company that was selling lightly modified 73-74 B body LCAs for use in earlier models. The design allowed for more suspension travel.

[Mike DC]

 
Yeah the 73-up LCAs dip down farther in the middle which gives more bumpstop clearance.  I can't remember who was selling that conversion for the earlier B/E cars.     


I'd be curious to see how the 73-up K-frame would ride if it had a different bushing setup.  I'm picturing something that still uses rubber bushings, but the bushings would be shaped to hold the K-frame tighter on lateral movement. 

Many modern cars & SUVs have isolated subframes and they don't always feel too mushy in the big picture. 

[Kern Dog]

Firm Feel defaulted to solid spacers, I recall Mopar Action's Rick Ehrenberg suggesting cast iron.
I had a 76 Camaro that had a subframe that used rubber cushions between it and the structure of the car. I replaced those with plastic pucks to improve handling. I used what was actually the white plastic polyethylene we use for cutting boards in kitchens. It was 1/2" thick and had a small amount of cushion compared to steel spacers.

[Mike DC]

                           
Yeah most people who care about handling choose to lock out the subframe's movement with solid spacers of some kind.  Metal, or at least a plastic/polyurethane (which is close to solid).

But the factory used rubber isolators for valid reasons. I like the idea of keeping that extra ride smoothness without having sloppy cornering.  Modern cars seem to pull it off.  It's just something I might experiment with if I ever built a 73/74 B-body. 



I think the rubber LCA bushing on our old Mopars is too thin (the rubber layer).  They wear out too quickly, they transfer too much NVH to the chassis, and they transfer too much stress to the K-frame mounting tubes. 

I've wondered if Mopar's engineers ever experimented with making that bushing thicker. It seems like an easy partial fix for some of the issues that made them isolate the whole K-frame in 1973.  And they could have improved an issue on all the A/B/C/E-body cars with one re-tooling.  IIRC all Mopar cars used that same LCA bushing in the 60s/70s even though the actual LCAs & torsion bars varied. 
 
 

[Kern Dog]

The thin lower control arm bushing probably does transmit more harshness to the cabin than the big bushings found in other cars with an actual A design for the lower control arms. MY 76 Camaro had big bushings in them but it was still a great handling car.
I don't see a way around it for our cars though. I don't know how you'd be able to modify the car or control arms enough to use a bushing of larger mass to cut down on the harshness.
It is an interesting idea, maybe someone with the skills to fabricate custom LCAs could come up with something. I don't know that the gains would be worth the monumental effort though.

[Mike DC]

                 
That's my read on it too.  The idea might be valid but there's no way to implement it without doing way too much custom building. 

There isn't room to bore out the control arm's T-bar anchor piece to fit a bigger bushing.  And I don't know if a bigger suitable bushing even exists or if that would have to be custom too.


The whole LCA inner pivot area is just a bad design compromise IMO.  I like the torsion bar design in theory but they tried to make that LCA do too many jobs in too small of a space. 

It probably needed a layout that involved two separate rubber bushings - one between the LCA & K-frame, and another between the LCA & torsion bar. 

[Kern Dog]

The LCA bushings are thin on rubber but the urethane ones do give a noticeably rougher ride.
In the early 2000s when there were at least THREE major vendors making suspension rebuild kits, they all seemed to push the urethane angle. PST, Energy Suspension and Just Suspension all had kits with rubber or with urethane. I bought into the hype and installed a full urethane kit. After awhile, I swapped in rubber LCA bushings, then rubber offset UCA bushings. I still have the urethane bushings in the strut rods.
My car rides pretty decent. It is about as firm as the wife's 2015 Challenger R/T with the Super Track Pack option group that came with stiffer suspension and better brake pads.
I still get road noise that would be great to reduce, though I don't see it being possible to tone it down that much.
These cars were not built to be quiet like new cars are. The rain gutters, drip rails, exposed windshield wipers, vent windows and recesses tires/body overhang all conspire to grab the wind, not slip through it. Add to that a solid lifter cam, headers and 3" exhaust!

[Mike DC]

 
IMO the polyurethane boom has a lot to do with GM cars that are covered in thick rubber donuts and floppy perimeter frames.

A/B/E Mopars had much tighter bushings & frames from the factory.  I'm a fan of keeping them all rubber. The material is fine & preferable as long as it isn't worn out from age/mileage.

Yeah, the rubber parts need to be replaced periodically.  So do spark plugs and clutches and seatcovers and everything else.  If you never want to replace parts then you're in the wrong hobby.

 

[Kern Dog]

 
Yeah, old cars are not maintenance free!

[Mike DC]

 
This might have made the Mopar LCA bushings work better from the factory - A newer bushing design with the center layer of steel in the rubber.  IIRC modern Mustangs have them on the front LCA.





The extra metal layer stiffens the bushing for lateral movement (handling), but it doesn't stiffen the rubber up as much in other ways like twisting forces (normal up-down suspension movement) or big impacts (car hitting curbs/potholes).  So you can run a bigger bushing without it feeling too floppy in handling.   

Part of the reason to want these things in our cars' LCAs (if it was possible) would just be longevity.  With softer twisting resistance the bushing would last much longer in daily usage.  And it might have prevented the problem of Mopar K-frames getting fatigue cracks around the LCA mounting tubes.  Too bad this bushing design wasn't around 50 years ago.   

[Dino]

I got these Longacre toe plates today. Correct me if I'm wrong, but shouldn't they be flat and parallel to each other in order to have a correct reading? These are not straight. This is with one end touching. Maybe I should just stick with strings.

https://a.co/d/0anAYBb1