I have had both ethe 470TA and the 670TA, i can say that i did not notice much difference in the preformance. I have a mild 302 pretty much stock with headmans and a edelbrock intake manifold. when i had the 470 on i just could not get it dialed in, and it sputter on the take off and was ok when gasing it, just the stop and go sucked, it also was an earlier one so it was made crappy, when i called holley they said "OH, its to small for a 302 you need the 670" i said to them everything i ever heard says you should stay under 600cfm for a stock 302, anyway they let me swap it out for free even tho i lost my receipt. when i got the 670 i was able to tune it ok, but still had the same exact problems of the 470, i think it is just the mannerisms of that carb line you just can't tune them for street, i have not yet heard anyone that can, but off road its great, i took it up some pretty steep inclines no sputter and coming down no sputter in the lower gear high rpm range it works flawlessly. the pro about the 670 if you decide to beef up your 302 you are set on a carb.