PowerAddict

A buddy of mine is building a 383 for his 87 IROC. He picked up an old 4 main block, and also found a t56 to mate it with. What clutch and, more specifically, fly wheel does he need to do this?

Thanks.

86camaro383

clutch dont matter...its the flywheel. RAM makes a aluminim one, and centerforce makes a steel one.

PowerAddict

what would be the difference in the flywheels?

Kevin91Z

A steel or iron flywheel gives you more inertia to get the car moving from a standstill like in drag racing.

An aluminum flywheel is lighter and turns easier at higher RPMs, for road racing and autocross.

PowerAddict

well, I guess, how will we know which flywheel is right. Like the actual difference between early model blocks flywheels, 2 piece blocks flywheels, and lt1 blocks flywheels?

86camaro383

early block and 2 piece RMS are the same, which are any block made 1985 and earlier. LT1 and and blocks made in 1986 and later are 1 piece RMS.

Rams aluminium one (which is the one I have, its a very nice piece) Jegs part number :798-2555

Centerforces one : 183-700173, thats a jegs part number as well. Those are 2 piece RMS flywheels.


The actual difference is the flanges it bolts up. http://www.thirdgen.org/techboard/tr...ap-thread.html
if you read the posts, youll find pics of what im talking about.

drptop70ss

If he plans on using an LT1 T56 with the factory LT1 bellhousing and clutch he will need an adapter flywheel to work with the 2 piece RMS engine. It is an expensive piece but available through the aftermarket. If he is starting from scratch it would be cheaper to build a one piece RMS engine so he could use the factory LT1 flywheel..or use an LS1 T56 and an aftermarket bell to use the facotory 2 piece RMS flywheel, clutch, and mechanical linkage.

PowerAddict

Yeah, he's got a 2 piece RMS block using an lt1 6 speed.

1 DWN CAM

Mcleod makes a LT-1 flywheel with 2pc rear seal. PN-460370 for 0-balance and 460370-2C for external balance. This will only work with the "Pull Style" Valeo p/p and disc.

c1989rs

http://www.summitracing.com/parts/RAM-2555/
this is the flywheel i am using and any t56 clutch will work i have a stage 3 clutch in mine depends on what u plan to do with it