the pushrods save some space since the vg has 4 cams and is pretty damn wide. im not into v8s but im assuming the 428 is a pushrod. if it fits and u have easy access to the parts i say do it. but a 4 speed? i dunno about that. im not even happy with 5. how do u cruise on the freeway with 4 speeds. unless the last 1 is long ass hell.