Technical SBC flywheel

I originally bought this flywheel for a 283....

http://www.summitracing.com/parts/nal-14085720/warnings/

I now want to put it on an '87 305 roller block. The application in summits description calls for this flywheel to be used up to '85.

Can anybody tell me why I cannot/should not use this on my '87 305?

Thanks,

Chuck

 

SBC main difference in 283 and your 305 is one piece rear main seal.

 

You have an engine with a neutral balanced dampener, and requires a weighted flexplate or flywheel. The reason? On the one piece seal blocks, the flywheel end of the crank is completely round, to work with a one piece rear main seal; the balance pad had to be deleted for that, and was therefore added to the flexplate or flywheel. Just look at the cranks flywheel/flexplate end and compare the "older" VS "later" engines. 87 was the changeover to the one piece rear main seal. I hope that makes sense. I am Butch/56sedandelivery.

 

Will the 283 wheel even bolt up to that round crank?

 

The $64k question... how many 283 flywheels do you want? Probably a few in the cl***ifieds or just buy the right one. They're available.

 

The bolt pattern on the later one piece seal crank is a smaller diameter than the old 283 crank.
An early flywheel will not bolt to a late crank.

 

I've also ran into about .100 thousandths flywheel height differences even in 2pc seal apps when swapping a SBC to Vehicles they didn't come out in. The hydraulic clutch years can and often have different flywheel thicknesses beginning in about 1985 up. I remedied this by finding the correct height pressure plate. Be simpler for you to hunt up an older 2pc main flywheel. Good luck . Flux

 

Great reply, Butch!
(I was unaware of the deletion of that counterbalance at the rear of the crank on the 1 piece seal engines)
Good useable info, as always.

 

Thanks all.....hopefully Summit will make the exchange for me. Now to find out if the clutch package i bought will work with it.

Chuck