Hello my name is nathan and im starting to do a restoration on a 1989 mustang, body is in the shop getting work and new paint so i am taking apart the motor to have cleaned, and machined as well as stroked to a 347 and i was looking at aftermarket heads and the question i have is the two choices are either stud or pedestal rockers, what is the difference, which is stock, which is better and can handle more HP and are they interchangable? in not how can i change them?