I have an '87 NA in need of a tranny rebuild, and the clutch is weak. I have a '90 t2 lightweight flywheel, heavy duty centerforce clutch, trans and driveshaft. Can I bolt this stuff right in? Also, there's a counter weight for the flywheel, but not sure what its off of. Can I tell by the weight if it what it came off of?

 

everything on the turbo models is bigger, so if you plan on using any turbo parts from the flywheel back then you need to use ALL of the turbo parts from the flywheel back.

you also can't use a S5 flywheel on an S4, the balance is different as the series have to match. ie 86-88 are interchangable within that year frame, as is '89-91 but you cannot use a flywheel from the later models on the earlier ones and vice versa. the counterweight can be changed but you would need the early model one, not the late model one if it came from the '90. (doesn't matter anyways, unless you get a turbo transmission as the n/a transmission will not work with the turbo clutch, input shaft is too small to fit the larger clutch)

the driveshaft is also too large to fit into the n/a transmission.