well any stock iron pontiac head is going to roller cam is hard to get the set up on the valve springs that will not pass coil bind ..as for guys with number block s i done more then one and not just chevys every one wants more power out of there muscle car with pump gas .the only thing it can do is move up the cid of the engine move to a roller cam to get the power they want to see out of there car . most all the time the engine cam be put back to stock