Not going to start a war with me, I do think the closed chamber 273 heads are the best for 273s, no chamber overlap like a 302 head and I thought they flowed more not less than the 302 They made great power in the 273 4bbl motors. I put a set of 315 on a 318 roller motor and it made plenty of tq for the full size conversion van it was in, I had to mod the intake bolt holes and PR holes but it ran better than the 302 headed motor ran.

I do not have a 315 head right now but I do have some 920s that should be legal and use the normal intake bolt angle and when I had them next to a 315 I couldn't find any significant differances, mabey you could fill us in