i have had some big engine on the street my last engine build was a572 tall deck this was not all out .one 4500 holley 9377 and a isky roller cam not big 12 to1 this engine made 760 torque and 800 hp before 6500 not bad ?you will need a set of custom hedders and the oil pan gets bigger so you may have some work to do . but the 572 and 632 is a new game not the same as your 502 but so much torque you will have fun hooking it up .as for merlin stuff it is hi on price. i have a big tall deck donovan thats in my 66gto all aluminum i do not have 15000 + in it like you would have with the merlin and it is lite the weight is 450