Chevy produced 454's for a lot long time than 502's. Both now replaced by 496. This new motor does not have the lack of a water cooling passage between the center two cylinders (nick-named "simese") like the 502. Thus the 496 is closer to 454 than 502. But it is way different, just closer when you compare to 454 or 502. Stock 496 is more powerful than stock 502 and is designed to last longer. Stock injection is way more udated too. Hot roders like to play, this newness makes it harder to play as the is no path to follow and improve on. The new design may have new engine bugs (problems) like all new products.