I think most of the time the guys that bought the crossrams in the old days put them on stock 302 motors. If you wanted to change cams and pistons it would be like the old modified eliminator days of the early 70's. Dual quads high compression, and a high lift cam. You really don't need all that compression on the street. Just a very low gear. 4:88's or 5:13's if you want all that cam shaft.
JMO Sam