valves
I had these same questions, except I stated I was on a tight budget. from what I found out, the after market valves will be heavier, but will flow better ofcourse. I was told to expect to see around 5cfm gain between stock valves and aftermarket valves. maybe a bit more if you go bigger valves. also, some of the valves Ive seen are flat across the bottom, not sunken (perhaps where the extra weight comes from?) which would result in higher compression at no Ptv clearance cost. not sure how much, Im guessing 1-2cc worth.
Ive heard good things about the REV valves.
Id also love to hear others opinions on this though. maybe my next set I will replace the valves on.
for me, i decided to keep stock valves on my new heads that i ordered, because i'm not trying to squeeze every little hp i can get out of it, the cost was not worth a minimal gain.





