Hi, i m looking in to buying cam for my C5, and I came across skunk 2 and i know i want to go with stage 2 instead of 1, but i just want to know wat are the differences between their stage 2 cam and the pro series 2 cam, they are like $50 different. Also, i am planning to get teh ti retainers, and valve spring and cam gear from skunk 2 too, is there any other thing i should change when i put in the cam? thx