Question on new clutch/flywheel sizes

[quicksilver]

Here's my scenario. I'm looking to get a new GM 350 crate motor for the truck. It's got a 3 speed tranny and I figured on changing the clutch out while I had it apart.

Summit says the OEM replacement for the clutch is 11", but looking at the GM flywheel (P/N 14085720) it says it's for a 10.4" clutch. If I get this flywheel will it work with the 11" clutch? I think it will, but I want to be sure.

It's got a 307 in it right now (installed by the 400 pulling previous owner), so worse comes to worse I could have the flywheel resurfaced and reuse it. I'd just rather have the comfort of having all new stuff.

Thanks for any responses.

[jimfulco]

That flywheel won't work with the 11" clutch. The pressure plate bolt pattern is not the same, and there's not room for the larger pattern on a small-diameter flywheel. Not to mention you'll have problems with the starter not meshing with a smaller flywheel. You need flywheel #3991469 for an early 350 with 11" clutch.

Also, flywheel #14085720 is a lightweight flywheel that will make it difficult to get a heavy vehicle moving from a dead stop.

[quicksilver]

Thanks jimfulco!!