Boy, I can SURE vouch for THAT! I didn't think the cam in my 351M was anything but stock........until I recently had to cut the tail pipes off to gain clearance for an extra capacity gas tank. Anyway, now I can hear an ever so slight bump to the engine. I replaced the valve cover gaskets the other day and for giggles measured the lift. not quite .484 on one side and not quite .512 on the other.......that's Ford's version! LOL I thought the old engine ran too dang strong to be totally stock.