[blykins]

Don't use an old cast iron flywheel. Too many instances of them coming apart at rpms. Very unsafe.

Flywheels are pretty inexpensive for the FE. I offer brand new billet steel pieces for $225. New aluminum ones start at $385.

For such a large amount of money spent on an engine, it's worth the insurance to spend an extra couple hundred bucks for a nice flywheel that you don't have to worry about.

For future reference, if you have a flywheel that you would like to use and it's not matched to the rest of the rotating assembly, you don't have to tear the engine down to use it. Most machine/balance shops can balance a flywheel by itself. So if you have a neutral balance wheel and you'd like to use it on a 428, then the shop can balance it and stick a 28oz weight on it. Conversely, if you have a 428 flywheel and you want it 0 balanced, they can remove the weight and neutral balance it. It's just a matter of balancing one flywheel against another known flywheel.

Your aluminum flywheel would probably work just fine, but you'll spend more money on having it machined and fitted with the friction plate and having it drilled than you would on buying a brand new one.