I am trying to figure out what needs to be done to put a T56 behind a 400. I know that I can order a $360 centerforce flywheel which is made just for this, but I'd prefer to do it cheaper if possible. Summit sells a bolt on counterweight, which sandwiches inbetween the crank and flywheel, but I am nut sure how that would work, since it would move the flywheel back a little bit. I guess its not enough to matter though. Would I be able to use this bolt on counterweight with a stock LT1 flywheel? Or would I stil have to get the flywheel machined for 2 piece rear main seal?

 

The LT1 flywheel has a different bolt pattern than the 400 crank hub...you'd likely spend more $$ trying to have it machined to fit than just buying the aftermarket flywheel.

 

i used that balancing plate that you are talking about. i got mine from goodson. i don't have a T-56 trans. it moves the flywheel forward an 1/8 of an inch at most. i have the balancing plate on my 305 flywheel. it works. i don't know how much of a beating it will take.

 

Would an early (2 pc rear seal) T5 flywheel work with the balancing plate and a T56 clutch? Im pretty sure the bolt pattern for the pressure plate is the same.