I'm rebuilding my engine and I'm going scat 383 rotating assembly, 200cc heads, mini-ram, zz409 cam. I've read from others that have the same setup that it makes around 470hp/450tq. I've already got a 94-97lt1 t56. Can the trans. hold up up to those ratings?

 

Sure thing, the T56's are strong. The only weak point is the 3-4 shift fork. They come aluminum and you can replace it with a steel one from most aftermarket trans places.

 

well all the synchro keys and plastic fork pads are weak links as well. I just had to rebuild a $3500 D&D "built" T56 when the plastic fork pad took a dump and trashed 3rd gear and synchro.. The gears themselves are good for 800lb-ft, as long as you don't have to shift.. LOL.. The shifting upgrades can get you nearer to that rating..

 

The aluminum 3/4 fork is really only an issue if you use a shifter without stops. A Pro 5.0 shifter will negate the need for the steel fork. There are upgraded billet or forged synchro keys available to prevent the stock ones from cracking (more common that Tremec would like to admit). I was never a fan of those plastic pads myself. Now I know why...

 

This isn't the case actually.. The 3/4 forks bend during quick/hard shifts, not from over extending the shift.. The T56 has internal stops on the shift rail so it doesn't require shifter stops. Aftermarket shifters have stops because they work on other transmissions (TKO, 3550, etc.) which do need the shifter stops.

 

A T5 has the same style of internal stops and they don't prevent the forks from breaking if you bang the gears too hard. Bending forks is a myth. They don't bend; they break. Either the internal stops are not sufficient, or you can extert enough force to flex the rail and allow the fork to overextend. The fork could also break from the synchro assembly getting hung up during a hard/quick shift as suggested. Put it this way, I run the steel 3/4 fork and the Pro 5.0 and have had no problems. I think the fork is $50, so it's cheap insurance if you're already tearing into the trans.

 

This is a good "If your rebuilding a T56, replace these with better ones" thread. Is there a sticky for these fixes or a place that illustrates what you "might as well fix" when rebuilding a T56? I'm going to bookmark this, cant wait to do a T56 swap. Ill probably fix all those problems first hand.

 

There's a sticky for the T5 and for T56 swaps, but maybe we should start one for rebuilding and beefing up the T56. I know this trans pretty well and would be willing to contribute.