I know this is quite late, but I just saw this post. On the 30 degree seats, Jim Hand (Joe H's dad around here and at Stovebolts site) is a Pontiac guru and has a super how to hop up Pontiac V8 book.
In it he explains why he uses their 30 degree intake seats rather than switching to the common 45 seats (more a mfg econo move than to make anything "better"). This is a good tip for a street motor--wish Tom Lowe could do a flow test at the least on this matter.
Jim Hand is super good and thorough on his testing and research. It does well to remember other makes and engines got good stuff going for them too. I'm not above listening and copying when I can.
In a nut shell 30 degree intake seats have more flow at the early opening and late closing and can be more beneficial than having better flow in the .500" lift areas (more "total flow", its free and it happens twice per intake cycle)
Last edited by preacher-no choir; 09/24/13 01:39 PM. Reason: spelling
