4 speed VS 727 question

[Bad B-rad]

What are the foward  gear ratio's in the 4 speed vs the 727 auto?
Thanks.

[c00nhunterjoe]

Depends on the 4 speed and the 727.
But for the most part 727s are 2.45, 1.45, 1. 833s could be 1 of 6 options. 2.65,1.93,1.39,1.//  3.09,1.92,1.40,1//
2.44,1.77,1.34,1. // 2.66,1.91,1.39,1. // 2.47,1.77,1.34,1. // 3.09,1.67,1.00,.73

[John_Kunkel]

ALL 727's are 2.45, 1.45, 1.

[Bad B-rad]

So the 4 speed is just tighter in the 2-3 ratio, then the 727, it will not offer lower cruising rpm (all things being = between the combos) Again LEAVING OUT the 4 speed overdrive transmissions.

[XH29N0G]

Correct,  They all end up 1:1

[c00nhunterjoe]

ALL 727's are 2.45, 1.45, 1.

So a 2.74, 1.54, low gearset does not exist for a 727?  Or a 2.77?

[Troy]

So the 4 speed is just tighter in the 2-3 ratio, then the 727, it will not offer lower cruising rpm (all things being = between the combos) Again LEAVING OUT the 4 speed overdrive transmissions.

In general "non-OD" transmissions have a top gear of 1:1. So switching from one to another shouldn't make much difference on the highway. However, the 4-speed may spin slightly lower because it doesn't slip like the torque converter in the auto. (Unless you get one with a lockup converter.) Having more gears just makes the jump between each smaller.

Troy

[John_Kunkel]

ALL 727's are 2.45, 1.45, 1.

So a 2.74, 1.54, low gearset does not exist for a 727?  Or a 2.77?

Correct. The only low gear sets are in the 904 family.

[Bad B-rad]

So the 4 speed is just tighter in the 2-3 ratio, then the 727, it will not offer lower cruising rpm (all things being = between the combos) Again LEAVING OUT the 4 speed overdrive transmissions.

In general "non-OD" transmissions have a top gear of 1:1. So switching from one to another shouldn't make much difference on the highway. However, the 4-speed may spin slightly lower because it doesn't slip like the torque converter in the auto. (Unless you get one with a lockup converter.) Having more gears just makes the jump between each smaller.

Troy

OK cool.

How are the late 70's 4 speed transmissions?
Will they handle torque?
And what are those ratios?(1-3 tighter then reg four speed and then 4th like 0.78???)


Like would someone looking to keep cruising rpm @ 65 nice, would he be better off using a 3.23 rear, and an 727, or 4 speed, or would a late 70's OD 4 speed with maybe 3.55/3.91's be better?


And the ratios above are just for arguements sake, I think you can get the just of my question, having the OD will let U run a deeper rear gear then non OD trans, is that better, or better to run the non OD trans with smaller rear

[XH29N0G]

The late 70's OD 833 in the aluminum case are not ideal.  I used one with a 3.23 rear from the mid 1980's until about 2011.  First gear was used up very quickly, the other shifts are big changes in RPM and not good for the power band.  My engine was a 383 at that time and I didn't blow it up, but I believe they are weaker than the other 833s.  I switched the rear gearing to a 4.30 and first was used up even sooner.  The OD is nice and helps with cruising, but I don't know if it is worth it if you want it for performance.  I used the car as a daily driver for some of that time and it worked fine on longer trips.  Now I have a stronger engine and a 5 spd Tremec with 0.64 final (so still OD but stronger and closer gears).  That one has had its own issues and taken some time to get right.  I think it depends what you want. 

[Bad B-rad]

How did the tremac fit?
Did you have to cut torsion bar X-member?


I am not sure what I want, I was just gonna do a 727, like stock, but 3 weeks ago I met a guy with 4 Roadrunners 383 4 speeds (pistol grip) and a Cuda and Satalite both 383 4speeds, so I kinda left there with PISTOL GRIP FEVER!!!!!!


But if the 4 speed OD are not gonna take it, then that's out.
Thanks.

[Kern Dog]

The Mopar 4 speeds were built by New Process. They were designed to fit the Mopar cars and trucks so they fit without modification.
The traditional 4 speed without overdrive was not offered in the late 70s. If I recall correctly, after 1974 or 75, ALL 4 speed transmissions based on the 833 design were overdrive.

[c00nhunterjoe]

ALL 727's are 2.45, 1.45, 1.

So a 2.74, 1.54, low gearset does not exist for a 727?  Or a 2.77?

Correct. The only low gear sets are in the 904 family.

Coming from the trans expert i would have thought you would have acknowledged the aftermarket availability of lowgearsets for the 727, especially since gear ratio options were tbe main topic of this discussion.  So to the op, yes, you can most definatly change gear ratios of a 727.

[Bad B-rad]

ALL 727's are 2.45, 1.45, 1.

So a 2.74, 1.54, low gearset does not exist for a 727?  Or a 2.77?

Correct. The only low gear sets are in the 904 family.

Coming from the trans expert i would have thought you would have acknowledged the aftermarket availability of lowgearsets for the 727, especially since gear ratio options were tbe main topic of this discussion.  So to the op, yes, you can most definatly change gear ratios of a 727.

AH that's what I may be after, what ratios are available, to be played with.
I would have thought for sure the 4 speeds would have had different gears to play with.

[Nacho-RT74]

but 3 weeks ago I met a guy with 4 Roadrunners 383 4 speeds (pistol grip) and a Cuda and Satalite both 383 4speeds, so I kinda left there with PISTOL GRIP FEVER!!!!!!

https://www.forebodiesonly.com/forum/threads/slapstick-replacement.4004/#post-17841

https://www.facebook.com/autogripshifter

[Bad B-rad]

but 3 weeks ago I met a guy with 4 Roadrunners 383 4 speeds (pistol grip) and a Cuda and Satalite both 383 4speeds, so I kinda left there with PISTOL GRIP FEVER!!!!!!

https://www.forebodiesonly.com/forum/threads/slapstick-replacement.4004/#post-17841

https://www.facebook.com/autogripshifter



Those are great products!
But I have known about them for years, or at least the gun slinger made ones.
I was even gonna try and make a custom pistol grip for my NV-5600, with the HURST shifter I bought for it.


What I meant was I have four speed pistol grip fever!!!!!

My 69 is a column shift auto, and I kind of like that.
My 66 Charger has the full console, and that's cool, but I am digging the no console look!
If I did a four speed swap, I would go no console.
I am rocking the Buddy seat!!!

[303 Mopar]

I swapped my '68 Charger to a Brewers 4 spd and my '70 Cuda to a Passon 4 spd OD.  Both made a world of difference in the fun factor and performance. The Charger has 3.23 gears with a 505 stroker with a ton of torque. The Cuda has a 392 Hemi with 3.55's, so 4th gear being .80 is perfect for cruising at 70 mph.  IMO the best choice is the Passon 855 5 spd, but I've been on Jamie's list for 3 years now.   

[Nacho-RT74]

yes I guess it was really the fever about the 4 speeds LOL, but just took the word literally

[Bad B-rad]

yes I guess it was really the fever about the 4 speeds LOL, but just took the word literally

Yeah, I think it was a combo, of them both!!!!
I have only had 1 four speed car, and it was 20+ years ago.
I think it would be so much more fun then the 727!!!
But the complete is not cheep, and the car is original #'s car with all it solid CA sheet metal.
I know its my car and I can do what ever I want, but some part of me want to keep it all OE.(as far as NOT cutting any extra holes in it.
I don't know why, maybe because here in NY I have never owned a car so original, and complete, and rust free?


The four speed guy also showed me the difference in the OE, pistol grip parts, vs the repo.
He also didn't like the repo pistol grips, once he showed me, you could spot the difference between the two fro out side the car.
He actually swapped an original pistol grip with a repo in one of his rides because he drove the one road runner more then the , other car(I forgot if it was the Barracuda, or Satalite) 

He also told me one of the cars has the OD version of the four speed.
I may stop by this weekend to pick his brain about it.
I do know a few of his cars he runs 2.94 or 2.7 something rear ends.
He has never been to a drag strip, and sayes he never street races, and love the MPG he gets!
Once the weather here gets nice, I am sure i can get a ride in a few of them, then I can see for myself how they run, that may help me narrow my combo down.
I had a 68 Coronet with a stock 3182Bbl with 2.94s, but I have never had a big block with gears that low (numerically LOWER, but concidered a high gear)

[XH29N0G]

I just signed back on and the conversation has moved on.  To answer your question about the tremec.  Yes, I had to do a fair amount of cutting to get the driveline angles right.  Without this, I had a lot of vibration up around 70 mph that depended on whether I was on the gas or not, but the driveshaft is also spinning pretty fast with the 4.30 gears. Once in and set up, it is fine, but something that fits right in would be much nicer.  The others who have responded know more than me on these matters, so I will be mostly silent unless I see something I can add.

[Bad B-rad]

I am going to guess the cutting was of the torsion bar X member area?
Or  just the floor pan?

[XH29N0G]

in my case, both, but I had an older kit and I had someone do the installation for me.  If you are good with the metal work, it will be a different story.  

If you look at the transmission on the following page https://shiftsst.com/articles/cat/mopar/post/charger-satellite-coronet-gtx-super-bee-1966-1970/ there is a notch where the rear shifter position would be.  This was not the case for my transmission and when installed it needed to cut part of the crossmember.  Later, I sent mine to SST and they cut the notch.  I think the notch could mean no cutting would be needed.  It fits better now.  I do not know how many companies cut the notch, but I would suggest doing research as you are and then deciding.

I also had an issue with the front part of the transmission hitting the top of the tunnel.  That needed to come up some to make space, but once done, it was fine.  .  Right now it is set up correctly with the driveline angles and I like it a lot.  But it took me some time.  

As I mentioned before, I do some things to my car (have done basic engine work with bolt-ons, changed a cam, heads, changed the PS, and fixed the alignment of the transmission, and shimmed the rear axle, .... but I do not know nearly as much as many of the others here who have responded to your questions.  And it may be a completely different situation for someone who knows what they are doing, which may be your case.  So take my comments in the context of my level of expertise - that of a tinkerer who is learning as he goes.  

One additional thing.  The 5 speed is different to shift from 2 to 3 (push up rather than over) and I tended to hit the gate.  I changed the springs in the shifter to make it center more forcefully and that has helped.  I should just learn to shift, but I get to excited when trying to shift quick in the 1/4 mile.  On the road it has not been a problem at all.

[John_Kunkel]

Coming from the trans expert i would have thought you would have acknowledged the aftermarket availability of lowgearsets for the 727, especially since gear ratio options were tbe main topic of this discussion. 

Well, if you wanna play the aftermarket game you omitted the "Red Stripe" ratios in the 833 list.

[Nacho-RT74]

I didn't know about the aftermarket gear ratios for auto trannies! So, I could get less than 1:1 as 3rd for 727 ? What are the options ?

[Kern Dog]

I think that the alternate gear ratios are only for 1st and 2nd. Third is always direct drive.
Sometime in the early 80s, the 904 based transmissions had a change of gear ratios for 1st and 2nd.