what rpm can it take?

[Jeff Chambers]

Done right, the hydraulic rollers are NOT a limiting factor. I used to routinely spin STOCK lifters to 8500 rpm with higher spring pressures (and more duration) than most will run even with a solid roller cam. The Victor Jr. intake and carburetor combination wants to breath, RPMs is how you do it and RPMs are where you build volumetric efficiency.

Put it on the dyno and see where peak power is at. If the valves start to float before you get to peak power, then make some adjustments in the valve train. Set the preload at no more than 1/4 turn and a simple set of restricted pushrods should solve the majority of lifter-related issues. Valve float is generally related to the springs though, but there's always another set of springs that will solve that problem.

As far as spinning stock parts, I used the same stock crank for all of 2002 and 2003 in my Street Warrior motor, one year at 50 oz-in and one at 28 oz-in, shifting at 7200-7500 all season, both seasons. One year in a stock block, one year in a B-50 block. Crank never broke, sold it when I bought a Scat crank and as far as I know the guy who bought it is still using it.