Hello Everyone,

I'm in the process of collecting parts to swap T56 in a 88 iroc with an L98.

Does the 88 Torque Arm Bracket off a 700r4 work with the T56? or will I need a newer style Torque Arm Bracket 93-2002?

 

Are you talking about the bracket off a 700R4? If so, you need a 5 speed thirdgen bracket (bushing will still fit). Or you can use a 4th gen 5/6 speed bracket.

I got a bracket of a 5 speed V6 4th gen I believe and used the same Poly bushing off my auto.

 

Bullydawg,
I've got my 700r4 out and seriosly thinking about a t-56 install on my 87 Formula. I was wondering what year t-56 you put in your Formula? I've got 3.54 gears in my rear axle and wondering if I would like the 93 T-56 with 2.97 first gear or go with the stronger 94-up with the 2.66 first. Last time it was dynoed I was making around 385 ft tq at the wheels.

Thx,

 

Honestly, I have been kinda hunting for a 93 T-56 for the closer gear ratio's for a fun spare. If you don't plan on swapping out your rear gears, then a 93 might be the way to go for you. If you go on google, they have a T56/Tire Size/Rear Gear calculator that tells you all your RPM speeds and such. I went with 3.89, but I have a 96 T56 with the longer 1st. I haven't gotten to drive it with the 3.89's yet, but I have with 3.27 and 6th gear isn't needed up 75+ really. With your 3.54, you might be fine! All depends on what RPMs you want to be running.

 

3.42 is the minimum that should be run with a 2.66 / 0.50 T56 (in the ~3500lb 5.7L realm.)

The 2.97 would be fine and the narrower headset gears aren't a huge strength issue, but ratio-wise it offers no overall spread advantage over a 2.9x / 0.63 T5. Unless you re-gear 5th/6th so it has GTO ratios. Which is what I'd do with a 3.54 rear.

 

Thx for the thoughts. I might just go with the 93 m29 version. Right now just starting to look for one. Just would hope it can handle trips too the drag strip and a sticky tire launch that would b my biggest concern with the 93 I think the gear ratios specially first would work good.

 

I believe the 93 models were only rated to 400 TQ. Compared to 94-02 models with 450 TQ. If you're not planning on exceeding it, then I wouldn't worry about it either way.

 

This is due to the gear ratios. The shorter first gear is a strength compromise.