I have a set of 241 cast heads and I was told they were milled .010 how much does that reduce my combustion chamber cc? Heads are also ported and I don't remember if they were polished its been a while since I installed them (around easter this year)

 

best bet would be to measure the cylinder volume and then the chamber volume, then you could get your exact CR

 

.010 is roughly 1.25 cc's