500 Hp Slant 6

I had a video of my buddy's 292 stovebolt 6. Runs high nines ina race chassis Studebaker. That is a 100% filled factory block, massively lightened factory crank, aluminum rods, custom pistons, two DART V8 chevy heads cut and welded together, the deck of the block filled and re-drilled to fit, custom cam, custom manifold, single turbo, on methanol. I really can't see why you would want to just to prove a point.. But.. i was looking into doing a stroked 225 for my '65. There is a lot of room to make some serious power. it will not be cheap but I'm pretty sure you can do it or come very close NA on methanol and 290 inches.

edit - heres the link to the engine build page http://www.cdpautomachine.com/leo/assembly.html