My machinist buddys sees good almost great numbers out of em. Not chevy numbers but 320+ with minimal effort.
OOTB, not on my car. Id buy bear and have em done but then again im lucky and dont have to pay for machine work....
I would not reuse your valves. They wont be right.
I cant remember what the parts csme out to do build a set. My buddy gave me the mumber but i forget.
I will be buying a set most likely.
I think with a max effort port job we could see 350+ CFM.