edy, keep in mind i am not a expert on cams. my specs were recommended by comp cams. but here are some theory's. turbo grinds need/want less overlap of the intake and exhaust valves because of the pressure build up ahead of the turbo in the exh manifold. if there is a large overlap then the pressure would also have a better chance of making it back up the intake. this is also more of a moderate street grind, not for high rpm. maybe that is the difference. tom
