I think you're pretty well right on all the specs and such, but I thought the valves for the 2 heads have different length stems? The guy that is gonna do my head work says he can't do the needed work to fit the bigger valves, but I kinda think he's just lazy! My truck doesn't exactly rip right now, but once I build it up some it should atleast get out of it's own way. And I'm a firm believer in having atleast 2.5" exhaust, that puppy hasta breath!