Well, not wanting to put a "hex" on your build, but any of the GM-based V8's could donate parts if you needed them.
For example, if your cat takes a fancy to one of the smaller parts...
Or, maybe down the road you might want to swap engines for something a little more updated? The GM LS1 V-8 is a very popular "crate engine" that can run on modern pump gas, has fuel injection instead of a carb, programmable ECU, better fuel economy and emissions, etc. and many classic cars are getting them installed.
