[flipper35]

Another thing that the Desktop Dyno may not take into consideration is the lifter bore size. For instance the small block mopar bor of .904 inches allows for much quicker ramp speeds on a mechanical lifter as opposed to say a small block chevy at a .842 (small block fords are .875). In this case a roller would be a more significant improvement in the sbc than the sbm since the rollers have no edge to catch on a small bore with faster ramps.

I don't know what the bores are on your engine, but it is something to think about.