So here is my problem. I have 2 T56s I know, I know it's a good problem to have. The first is a freshly rebuilt 98 tranny with a full 6 speeds in upgrade kit (billet keys, carbon syncros, steel forks...), also has the stronger 2nd gear since that was shot and necessitated the rebuild. I also have one from a 96 Z28 with 30kish on it. Bone stock but I have the bell housing and slave. Trying to decide which I should use behind the 408 I'm doing for my 89 should be about 520-550hp on motor might do a 100 shot but not for a while. I got a good deal on both and now I'm selling my other car so I was going to use both and now only need one. I know to use the LS1 tranny I need a Mcleod modular bell housing, but to use the LT1 tranny I would have to build it up to hold the abuse of the motor. I don't have a flywheel or anything yet so anybody have thoughts either way on this?

 

I have heard that the input shaft will need to be changed out on the ls1 tranny. If you dont have the slave cyl spacer, look out! It's been discontinued and I have been searching everywhere for two weeks and cannot find one anywhere!

 

The LT1 trans. are actally stronger. That spacer comes with the bellhousing, new from GM for 400. I got the whole bellhousing off a 4th gen forum for 75 shipped.;..

 

That may be stock for stock but the LS1 trans has been built to hold 700 whp and tq. Only other mod that could be done to it is a viper mainshaft which would be total overkill given the power level and vehicle weight.

 

what are you putting it behind?

 

in his original post he said he was putting it behind a 408. 520-550HP