BBC Compression
 

I have 15.03 :1 compression on a 565 now, I want to change heads but if I do not cut them it will have 13.79:1 . Any thoughts on if that would be a mistake not to cut the new heads?? I thought that to cut them puts the spark plug farther behind the dome of the piston as well.

I personally would want to keep my compression the same..i have PAR 565ci and he will not build a hp 565ci less than 15:1
the compression simply makes the power.

Just curious what kind of heads you putting back on and what you got on there now ?