Has anyone tried a flywheel from a SBC on a BBC to save some weight? I'll go internal balance,use a different balancer and get the weight off the ends of the crank.Any ideas.BOB

Weight savings? Why?
You need a decent flywheel to keep your idle quality.

If you're dead set, then why wouldn't you use an aluminum big block flywheel?

A SBC 30 lb flywheel weighs the same as a 30lb BBC flywheel. GM does make a light weight flywheel it's ribbed on the back not a solid casting. I think you want the momentem to stay up on the motor. Besides, all the the SB 400 is internally balanced, where the 454, 502 is ext. balanced.
Mike

What I meant to say was remove weight from the ends of the crank by going to internal balance.I'm building a 540 and didn't know if the flywheels were the same weight.Thanks for the replys.BOB