Don't have time to wait for my cc kit, so my engine guy is going to cc my heads on Monday. I used to work for him years ago. He insists I shouldn't have a problem running 10:1 compression on pump premium and he's been building great engines for years, so I trust his input. However, once I find out chamber size, I'll get thick enough gaskets to bring compression down to 9.5:1. Just for peace of mind.