Most of the people I've known that put after market cams in an engine tend to be heavy on the throttle, and wind 'em up to feel the extra power and acceleration. These flatheads are torque engines and do not like high RPM's. If you put an Isky, or any cam other than stock in, keep the grind mild and don't continually wind it up. The hotter you make an engine, the shorter its life. These flatheads are best enjoyed for what they are. I love the way I can slow to 10 mph in high gear, ease into the throttle, and it just starts pulling. No bucking and jumping, it just goes. An important feature when they were made and the roads were poor.