Getting a smallblock to rev

Buy the strongest, lightest crank you can run (will they let you trim it down?), ditto the rods, and you might think about aluminum flywheel and a four speed. With that high, narrow powerband you're going to want to keep in the powerband as much as possible and that spells four-speed.

If aluminum is not legal, run the smallest flywheel you can get away with. Good valve springs, light valves, and light pistons.