The 216/235/261 engine is pretty much a lost cause for performance modifications, particularly if high RPM is involved. How about starting the party with a 230 engine? It's got a big bore, a short stroke, a cylinder head that can be modified for much better intake and exhaust flow, and it's 50 years newer than most of the other stovebolt sixes. A side draft Mikuni carburetor for a Harley EVO engine is designed to feed 80 cubic inches, so three of them on home-brewed adapters to the cylinder head would eliminate an intake manifold altogether and the volume would be just about ideal for a 230. "Why not a 250 or a 292"? The short stroke would allow that engine to rev somewhere into the high 7K RPM range as long as the proper camshaft and valve springs are used. That engine also has 7 main bearings, so the bottom end is stronger.

Yes, I'm considering building one sometime soon.
Jerry

Edit: Doesn't a quarter mile need four turns and a dirt surface before it can be called a "race track"??????

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