Big horsepower 318 builds

fishmens67 said
The difference will be in the rpm, I don't care how you slice it , 1.54 hp per cube with a 323 will need rpm

Didn't that 477 HP 318 that Adney Brown built make it at 6500 RPM? Not to mention he was limited to a 10.5:1 compression ratio limit, 91-octane pump gas, and a mandatory flat-tappet cam.

How much more will it take to get that extra 23 HP......