whats the difference between stage 1 and stage 2 and when u install them do u have much power difference?

 

It depends on the manufacturer..."stage 1", and "stage 2" are arbitrary terms that differ from company to company... Typically stage 1 cams don't require you to replace your valvetrain and yield about 10hp with a proper tune... Stage 2 cams require you to replace your valvetrain and yield about 15hp with a proper tune...