I like mine on my 455. Good finish and port alignment, I think I had on runner that I ground a snick off for gasket match. Much stronger low end rsponse ( it's a dual plane) and better drivability than the Holley Street Dominator I had it. It probably gives up a touch of top end pull to the SD but I don't spend a lot of time "up there" and the better driving manners (crisper throttle response) is worth the trade-off.
