Ok, rockers are a no no unless you are keeping the stock cam. Even then they are a waste of money. With the X1 you don't need to fly cut the pistons but like I told you before I would go more exhaust duration and lift and a 114 LSA for the juice and the auto. Putting the cam in a vette is a bitch because you have to remove the steering rack to get the pulley off. After that it shouldn’t be too bad, just don't move the steering wheel.
My heads are from Absolute Speed and the came is the Thunder Racing TR 230. Hopefully I'll have more power soon.