i think you guys misunderstand me, i'm not using a 366 block, i just pulled heads and intake off a 366t, thought the heads might be large oval port heads, they are large oval port heads like a 781 head, but they have smaller valves, i thoght the intake might support a 496 500 cubic inch motor with the high rise, i listed those ebay item numbers so you could see a pic of the manifold i was taking about, i think Mr. mccarthy knows what manifold i'm talking about, and yes you did tell me how to build/stroke a 427 tall block, thanks, i'm just not to sure on what i want to do with this project yet, i picked up the heads and manifold off that 366 for 60 bucks, had to remove them my self in the RAIN yesterday, thanks for the info