Ok Camshaft experts here you go!!

The cam lift on that. Imo cam is ground in and calculated with a 1.5 rocker arm ratio for a .544 lift. The Magnum rocker arm is a 1.6 ratio. This gives more lift which I should the math above. Your new lift is .580.

If your using the stock Magnum head, you will have clearance problems with the new lift spec.