What GM transmissions clear the trans tunnel without cutting?

[JR]

Well, after a ton of research, it appears my options are

Turbo 350= no tunnel mods at all, but no overdrive. I suppose I could fit a gear vendors to it, but that seems convoluted to go through all the trouble of a full drivetrain swap and stick that band-aid on the trans after.

2004r/700r4/4l60,65,70 = light hammering on the tunnel, but no cutting floor, but potentially a weak point in the drivetrain that will fail at some point.

4l80= absolutely Rock solid trans that won't fail, but requires a big hole in the floor and cutting and boxing of the center support.

I'm likely going to use the 4l65/70, and avoid any launches with slicks for the immediate build. I see the failure rate in them, but I can't bring myself to cut out my clean floor just yet.
  I can probably find a 5.3 or 6.0/4l65 pullout from the same vehicle to simplify things.

If (when)  the 65 starts to let go, I'll reconsider cutting the floor out then.

[c00nhunterjoe]

Just bear in mind, slicks are not the determining factor for burning up the 60. Its simple physics. The 60 is the same dimension as a 350, yet it now holds 4 gears vs 3. To do this, they shrink the inner parts to get it into the same package. No matter what upgrades you do, the clutch packs and servos are still the same small size, less then that of a mopar 904. Bfg radial ta tires will burn it up. My money is an overdrive failure or a 1-2 shift flare as the 1st issue down the road with it. Good luck in your endeavor.

[JR]

I gotcha Joe. I'm probably going to use a low buck salvage yard pullout engine/trans combo, so I'm not going to have a bunch invested in the trans itself.

If (when)  it lets go I won't be heartbroken. I can switch to a turbo 350 or 4l80 then.

I appreciate the help guys.

[c00nhunterjoe]

A 5.3 will probably be the easiest to get a complete and bolted together 2wd unit from a pickup. A 6.0 would be ideal but to find a package with a 4l60 will be near impossible. 99-06 being ideal as they are pre mds.

[Kern Dog]

Why even do this with a Chevy engine?
A 5.7 Hemi and a 518 would keep the car ALL MOPAR.  The 518 is stronger than the GM transmission as well.

[JR]

I suspect this is going to open the floor gates from loyalist, but anyway.

Kern Dog, the simple answer is Im way past the point of caring about keeping it all Mopar. That doesn't mean much to me anymore. And I want a modern engine and modern drivability now. I'm tired of the numerous quirks of a 50 year old big block.

And I don't believe the Hemi is engineered well enough to justify the outrageous costs of swapping one in. After witnessing a handful of my friend's LX platform cars scatter their engines on completely stock tunes with under 100k miles, I don't trust them enough to go through the trouble and cost of using it. The newest episode of Hot Rod Garage was a good example. They set out to build the cheapest new hemi powered classic Mopar possible and still went over 9 grand (after subtracting the $2500 cost of the Duster.)
That's almost 10k for a 345 horse, stock hemi before any power mods. That same money in any LS swap will go WAY farther. It's not even a comparison.

It's simply not worth it to me to spend two to three times the money, still end up with less HP, a less reliable engine with less aftermarket support and not have any real advantages aside from the fact I "kept it Mopar."

I'm doing the swap to be reversible, so I can always put the 440 back in if I want.

[Mike DC]

              
I'm not gonna hate on you for the brand issue.  But I will point out a couple things:


- One minute you are talking about running a junkyard 4L60E behind a modern ponycar V8.  The next minute you are saying a modern Hemi isn't durable enough.  

- An LS into a Mopar probably won't be like putting an LS into an old Camaro.   Motor mounts?  Oil pan?  Headers?  You may be hand-fabbing some (or all) of this stuff.  Just something to consider.  Whereas there are people & businesses to help with the G3 Hemi swap.


As for the modern Hemi - it seems like the blocks/heads are good strong stuff from the factory.  But the rotating assy & valvetrain parts aren't as solid.  The factory cut all those moving parts pretty close to the edge.  Saving a buck, helping it rev fast, and passing emissions.  

[JR]

Yes, Mike. The 4l65 is the weakest point of the swap, but I can change to a different trans later if need be and eliminate this issue. I'm deliberately taking the harder way out here to avoid cutting the car, this wouldn't be an issue otherwise.

 I prefer the headache of sorting the trans out over the headache of a 10 thousand plus dollar hemi swap that randomly eats it's bottom end, drops a valve, or any other stupid failure I've witnessed firsthand with the new Hemi.

And true, there isn't a drop in kit to put an LS in a b body. BUT, there is a huge list of LS powered vehicles to pick and choose parts from. And the costs of their parts vs hemi stuff is no comparison. TTi headers for a 5.7 hemi B body are 800 bucks. Factory Trailblazer SS exhaust manifolds are 80 bucks or so used. The newer GTOs used a rear sump oil pan, and if that one doesn't clear, there are countless aftermarket ones available.

[Mike DC]

  
Well, best of luck with it.


FWIW, I think you might be able to get a GM 700/4L60 series (or maybe 200-4R) trans that holds up if you throw enough money at it.  A production LS motor on regular street tires is not THAT much stress.  

Guys usually quit trying to make a smaller tranny work once it the cost climbs up way past the price of a bigger tranny.  But that's not an engineering limit. 

There's a bazillion GM cars out there and lots of them came with the light-duty trannys.  I imagine somebody out there has made the smaller trannys hold up by replacing half the internal guts with custom CNC'd stuff.  With GM parts, you name it and somebody has done it.

[c00nhunterjoe]

Or you could drop the k frame down and trans cross member down like the old drag race tricks. That would probably give you the clearance to run the larger trans and not cut or hammer the floor. The trans crossmember will have to be modified for any gm trans anyway.

[Kern Dog]

TTi headers for a 5.7 hemi B body are 800 bucks. Factory Trailblazer SS exhaust manifolds are 80 bucks or so used.

Now you are comparing headers to stock manifolds? Yeah...FAIR comparison. That is like Jamaal saying his dick is bigger than all the other 6th grade kids but that is because Jamaal is 17 years old.   

You do know that the 5.7 Jeep manifolds fit, right? The SRT8 Jeep manifolds might as well.
Durability? I have 342,000 on my 2007 Ram 1500.
The only late model Hemis that I know that have had valve seat problems are the ones that have overheated.

[JR]

Rather than make a long argument that will inevitably go down a rabbit hole, I'll just say the hemi isn't worth the cost premium to me. I've seen too many fail under too many different owners to spend the money on one.

Not to mention, If I was after power alone, I could have a stupidly built LS for what a stock hemi swap costs. I mean I'm not, but the speed per dollar spent is no comparison.

If it was comparable in cost, maybe then. But I'm sure not spending 10k just for the sake of "keeping it mopar." It's just not worth it.

[c00nhunterjoe]

Not that it matters, but more ls engines come into my shop blown up then hemis. Wiped cams, blown lifters, broken valve springs and dropped valves. Most are in the 100k range, bone stock.

[Kern Dog]

Heh heh heh.... 

[Mike DC]

                      
Just curious - which aspects of the old Mopar engines are motivating this?  

I get it, nothing is gonna compete with an LS motor on HP-per-dollar.  But you aren't complaining that your Mopar big block is too slow.


Have you run a good EFI conversion on an old Mopar B/RB engine yet?  I would think that, plus an overdrive gear, would do a lot to calm the annoyances.

The gas mileage would still not be great.  But that has a lot to do with cubic inches - an LS motor wouldn't be too easy on gas either if it was 440ci.  You could swap down to a 383 B-block without incurring a lot of changeover costs.  That's a damn good engine in terms of torque per inches/MPG.    




The easiest practicality gain would be swapping in a 1990s 5.2L or 5.9L Magnum.  Most of the EFI hardware you would need is already there, as well as a roller cam.  And those motors can definitely stay together for a lot of miles.  

But the 5.2L is pretty small and the 5.9L gets pretty bad MPG for its size.  

I've often wished Mopar had done a "Magnum" update in the 1990s for the bigger engines.  Imagine if the junkyards were full of Ram trucks with 383/400/440 big-blocks that had factory EFI & roller cams & decent aluminum heads.  We would be putting those in muscle cars all the time.  The 383s would probably be getting 350-inch gas mileage but making power/torque like 400+ inches.
 

[JR]

Basically Mike, I'm tired of the 50 year old tech, the power delivery and 5500 rpm redline, the lack of overdrive, the old school flange gaskets that constantly leak somewhere, 700lbs of weight on the nose, and all the radiant heat the big blocks put out. (The coolant stays between 190-210,  but as soon as I hit stop and go traffic, every fluid starts to cook and the passenger compartment turns into an oven. I've done a TON of work to mitigate this, still chase the problem in the summer. Just the nature of big blocks I guess.) 10mpg and cruising down the interstate at 2800 rpm with 2.96 gears. And the physics of all the iron on the front of the car don't work well for handling. That much weight on the nose sucks the fun out of driving. (I can't imagine how bad a Cummins swapped anything must drive.)

My 440 has been dead reliable. I've never suffered a mechanical failure from the engine itself, but it is tired and due for a refresh, and the reasons above stop me from wanting to spend the money on it.

Basically I like pro touring and GT cars, and I've gone as far as I can with the 440. Or as far as I'm willing to go.

I'll put the 440 back in one day when I've done had all the fun with it I'm after.

[Mike DC]

                                
I totally sympathize about the weight on the nose.  

IMO the Cummins swaps are ridiculous for all-around driveability purposes.  When you bring up the weight issue you hear things like "What's the big deal?  Put stiffer front springs on it."   If you drove a stock Charger with 500 lbs of cinder blocks strapped to the hood, the same people would point and say "Jesus Christ, that dumb fuck is destroying his chassis!"  
           

Good point about the gaskets.  The old ones work but they aren't as reliable.  


Interior heat, yeah, that sucks.  Long-tube headers are really bad about causing it.  The thin walled tubing acts like a radiator for the exhaust heat.  I wouldn't bet on an LS being a lot cooler unless you kept little stock manifolds on it. 

Ceramic coatings inside the headers/manifolds do help this issue noticeably. 

[c00nhunterjoe]

Basically Mike, I'm tired of the 50 year old tech, the power delivery and 5500 rpm redline, the lack of overdrive, the old school flange gaskets that constantly leak somewhere, 700lbs of weight on the nose, and all the radiant heat the big blocks put out. (The coolant stays between 190-210,  but as soon as I hit stop and go traffic, every fluid starts to cook and the passenger compartment turns into an oven. I've done a TON of work to mitigate this, still chase the problem in the summer. Just the nature of big blocks I guess.) 10mpg and cruising down the interstate at 2800 rpm with 2.96 gears. And the physics of all the iron on the front of the car don't work well for handling. That much weight on the nose sucks the fun out of driving. (I can't imagine how bad a Cummins swapped anything must drive.)

My 440 has been dead reliable. I've never suffered a mechanical failure from the engine itself, but it is tired and due for a refresh, and the reasons above stop me from wanting to spend the money on it.

Basically I like pro touring and GT cars, and I've gone as far as I can with the 440. Or as far as I'm willing to go.

I'll put the 440 back in one day when I've done had all the fun with it I'm after.

Now im really confused. Aside from the overdrive, all of those problems will happen with no matter what "stock" engine you put in the car. Its 2 tons of steel. My 6.0 pickup gets 14 mpg empty with overdrive, runs at 215 per the factory, and puts out enormous amounts of radiant heat in the summer.

Manifold gaskets blow out- dont buy the cheap ones. I do leaky ls manifolds on a weekly basis.
Really confused on what the "redline" of the engine has to do with a decision to scrap a 440. The ls doesnt spin much higher. What is the purpose? Torque moves the car, not the max rpm capability?

Every reason you just gave to ls swap the car makes no sense. The same "problems" you have now, you will still have. It sounds like you are just making excuses to put one it. I dont get it. If you want to ls swap it. Just do it.

[c00nhunterjoe]

Furthermore- regarding weight of a 440 vs ls..
A bone stock iron everything 440 is 675ish pounds. Aluminum intake drops 30 lbs, aluminum heads drop another 50 lbs, headers drop another 10 all conservativly. An iron block lq4 6.0 ls weighs 580 lbs.... so you do the math there and tell me where the weight savings in an ls swap is? Unless you are buying an aluminum block ls, which then negates your cost savings arguement.

[Kern Dog]

Careful...You are making too much sense and the OP is not interested in any of that! 

[Mike DC]

Furthermore- regarding weight of a 440 vs ls..
A bone stock iron everything 440 is 675ish pounds. Aluminum intake drops 30 lbs, aluminum heads drop another 50 lbs, headers drop another 10 all conservativly. An iron block lq4 6.0 ls weighs 580 lbs.... so you do the math there and tell me where the weight savings in an ls swap is? Unless you are buying an aluminum block ls, which then negates your cost savings arguement.

There's no way the B/RB motor family is cost-competitive with the LS motor family on weight.

An aluminum B/RB block is like $6000.  And that only buys the block.

[c00nhunterjoe]

Furthermore- regarding weight of a 440 vs ls..
A bone stock iron everything 440 is 675ish pounds. Aluminum intake drops 30 lbs, aluminum heads drop another 50 lbs, headers drop another 10 all conservativly. An iron block lq4 6.0 ls weighs 580 lbs.... so you do the math there and tell me where the weight savings in an ls swap is? Unless you are buying an aluminum block ls, which then negates your cost savings arguement.

There's no way the B/RB motor family is cost-competitive with the LS motor family on weight.  

An aluminum B/RB block is like $6000.  And that only buys the block.  

No, i meant the op said he was buying a used ls platform over a hemi because they are so much cheaper. Thats the iron ls, the aluminum ls blocks cost alot more. It was in reference to the weight differences.

And an aluminum headed, aluminium intaked b/rb is comparable to a 6.0 ls.

[Kern Dog]

That is how I saw it.
Placing your argument FOR the Gm engine based on low cost and low weight, this means a production block and heads. If you go extreme and use an aluminum LS block, the price argument loses it's merit entirely.
LS into a small import car for drifting? Sure.
LS into a sand rail for desert racing? Sure.
LS into a classic GM car for "whatever" ? Sure.
LS into a Mopar or Ford? WTF is wrong with you? The Ford Coyote and the Mopar 3G Hemi are RIGHT THERE in front of you.

[JR]

Annnnnddd there's the Mopar loyalist argument that I knew was coming.

Im not making excuses, I was asked for my reasons for swapping, I gave them. The LS (or any modern engine really) is better suited for how I want to use the car. The LS is the best fit for cost/packaging/aftermarket support and is easy and cheap to replace if I break it having fun.

As for the max redline question, I enjoy doing autocross and related stuff, where wheel speed in a certain gear is absolutely a benefit for car control. 

At this point, I am after a fun to drive and well performing vehicle for the money spent. I could absolutely care less about car show points or if a swap is "played out."

And again, the hemi is two to three times the cost to swap in. It is in no way two to three times the engine.

[Kern Dog]

I could absolutely care less about car show points or if a swap is "played out."

If you CAN CARE LESS, that means that you care by some amount. If you COULDN'T care less, that means that you don't care even the slightest amount.
Why even post this on a Charger forum? Your car seems like a decent ride. It isn't like you dragged this out of a soggy marsh and it was a rusty mess with no value.
I can see the appeal if your car was a worthless POS but it obviously isn't. How much of this is a matter of how you can irritate the Mopar crowd?
If that isn't it....How short on cash are you that you resort to an off brand engine?
I've read your posts here before. You seem like a reasonable guy but this is waaaaay off of the reservation.