4+3 trans swaps
Are you sure that torque arm isn't simply a trailing arm, and that there's a joint up near the trans where it pivots? If this is the case, then there is no torque exerted on the tailhousing of the T5.
Anyway, to get back on topic, I think T5 in C4 will work.
-- Joe

Imagine how much worse it'd be if there was no crossmember, and you simply bolted the beam rigidly to the trans.
Now the diff nosing up is going to torque the hell out of the trans casing, and the weight/momentum of the drivetrain sagging/bouncing is going to torque the hell out of it also. None of this happens on the Fbody. You simply need a stronger crossmember.
I wouldn't expect the T5 case to last on the vette simply based on it's setup in the Camaro.
-- Joe

Even with the Stock C4 setups the trans cases deform and output seals leak in back when overtorquing the cbeam bolts.
So far the Theory is:
4+3 Pedals and master
Howe hydraulic TOB
T5 out of an fbody
Custom cbeam adapter plate
Bell housing still up in the air.
-- Joe
The Best of Corvette for Corvette Enthusiasts
CentralCoaster and I have gone back and forth on this in a pretty detailed fashion in PMs, and he's been very helpful giving me measurements and his 2 cents and experience in doing his ZF swap. Other members such as LD85 have also given their insight. I've done all the calculations and it appears I can do the 700R4 to T5 swap using a lot of 4+3 parts as well as some fabricating for around $1100.
If of course, things blow up in my face, I will be sure to post my results. Either way I'll be posting and letting you guys know the progress. The 700R4 came out last night, and the motor comes out tomorrow. Once I've negotiated with a seller of the pedals and hydraulics, those will go in, and then after a cam change the motor will be back in along with bellhousing. I need to locate a decent T5 and a hurst shifter so I can made an adapter for the Cbeam and start on the shifter rod adapter.
The T5 and 700R4 use the same yoke, and the distance from the block to the tail shaft is the same, so they use the same length driveshaft.
I've taken all the critical measurements down prior to unbolting the 700R4 so I can be sure the pinion angle will be the same with the Cbeam adapter I will construct. When completed I will post the specs and measurements of the adapter, as well as materials. It will be made from 1/4" plate steel and mig welded together.
-- Joe
If you really want a 6spd, go with the T56 swap. It's stronger and there are more of them available than the ZF6.
I don't want another war, but I will state the facts. The T56 will bolt up to an ls1 of course, for $199 you can get the tailshaft adapter from pro street unlimited so now it bolts to the Cbeam.
If you have a L98, you can get a wier bellhousing which allows bolting of a stock T56, to a an SBC with traditional flywheel + clutch setup.
(you can use the 4+3 stuff!) It uses a hydraulic throw out bearing, so it's clutch agnostic.
A T56 swap is even better than a T5 swap in terms of strength, and the additional overdrive however I'm 100% positive it will cost more than a straight up ZF swap. ($500 for bell housing + tob, $199 for cbeam adapter, $whoknows for tranny, $250 for a good 11" flywheel, $300 for a good clutch, lots of time and patience).
I'm going with the T5 because the cost of ownership is lower, and I can break about 4 of them for the price of one ZF or T56. I can't use any lower overdrive than the T5 has to offer unless I re-gear my rear-end, or put a stock cam back in it. If I need more 'clutch holding power' I can step up to an 11" clutch by using an aftermarket OR Muncie (think 70s) bell housing + hydraulic throw out bearing.. But I've had pretty good luck with the 10.4" clutch + t5 combo in the fbody's so it should work fine in a lighter car.
-- Joe

What did you use for a clutch master cyl? A lot of thirdgen guys find the fbody master in the thirdgen doesn't push enough fluid to work the fourthgen slave.
-- Joe
I don't want another war, but I will state the facts. The T56 will bolt up to an ls1 of course, for $199 you can get the tailshaft adapter from pro street unlimited so now it bolts to the Cbeam.
If you have a L98, you can get a wier bellhousing which allows bolting of a stock T56, to a an SBC with traditional flywheel + clutch setup.
(you can use the 4+3 stuff!) It uses a hydraulic throw out bearing, so it's clutch agnostic.
A T56 swap is even better than a T5 swap in terms of strength, and the additional overdrive however I'm 100% positive it will cost more than a straight up ZF swap. ($500 for bell housing + tob, $199 for cbeam adapter, $whoknows for tranny, $250 for a good 11" flywheel, $300 for a good clutch, lots of time and patience).
I'm going with the T5 because the cost of ownership is lower, and I can break about 4 of them for the price of one ZF or T56. I can't use any lower overdrive than the T5 has to offer unless I re-gear my rear-end, or put a stock cam back in it. If I need more 'clutch holding power' I can step up to an 11" clutch by using an aftermarket OR Muncie (think 70s) bell housing + hydraulic throw out bearing.. But I've had pretty good luck with the 10.4" clutch + t5 combo in the fbody's so it should work fine in a lighter car.
-- Joe
Yes, but if you already have a ZF-6 in the car, the economics make the case pretty convincingly.
What did you use for a clutch master cyl? A lot of thirdgen guys find the fbody master in the thirdgen doesn't push enough fluid to work the fourthgen slave.
-- Joe
A company called "pro street customs" specializes in weird vette stuff. They make a cbeam adapter intended on folks whom wish to put a T56 into their C4 corvette.
They sell this thing for $150
http://www.prostreetcustoms.net/site...56-404x266.jpg
http://www.prostreetcustoms.net/site...l1-548x712.png
Well, GM iwhen they designed the 4th gen they didn't want to redesign the torque arm mounts and such, the T56 and T5 tail shafts appear to have the same mounting bolt pattern. Which means, for $150 the cbeam mounting issue could be resolved.
So I think:
1) new flywheel
2) New clutch
3) Used 4+3 BH,
4) Used 4+3 pedals + hydraulics
5) Cbeam adapter
6) Hurst fbody T5 'offset' shifter
7) Used T5 transmission (v8)
The offset shifter is designed to compensate for the 18* rotation of a fbody bell housing. The shifter base can be taken apart, and the mount reversed so now the shifter will lean over to the drivers side 18*. Then you just heat up the rod that bolts to the mount on the press, and turn it a hair to center in the hole.
Not bad for a 700R4 to T5 swap. If it works.....
UPDATE:
I spoke with Tom who owns pro st. He wants some measurements, but he told me worse case scenario, if I ship him a T5 tailshaft he will modify the adapter and start producing them for T5 swaps.
Again folks, a T5 will bolt the 4+3 bell housing. If you have a 4+3 that blew, this could be a solution for only a couple hundred bucks.
-- Joe
Last edited by anesthes; Sep 14, 2007 at 03:31 PM.


I put a ZF6 in front of 3.07 gears and all I got was a useless 6th gear and a too tall 1st gear. The upgrade to 3.45s cost me another $400 (and headache) in addition to the $1600 spent on the ZF conversion.
I like to see anyone putting the work in to open up the options for everyone else.
















