Purple Shaft or NOT?

The cams big swing in RPM is due to the displacement it goes in. The shorter the stroke, the higher the RPM. He gave you the biggest possible spread the cam could be used in.

Cam selection is a topic that can produce as many results and opinions as the underwear isle has styles for the ladies.

BRB, I gotta run out the door. I'll fool around with some dyno sym's for idea's. It's a good tool to play with and take with a grain of salt.

DO you have your cylinder head flow specs? This would be really good to have and a huge help in a cam choice.

OH, theres nothing wrong with the Purple cam. But a cam should be choosen with more info. The Purple cam is an old design that can make great power, but a different cam can yank out more HP and TQ.