Block Milling

I have the KB107's in my 360 at zero deck and I am using a Fel-Pro .039 compressed thickness gasket with the magnum heads. These gaskets have a very large bore (4.180") so they add some head volume. Anyway, my calculated compression is 10.5 almost 10.6 to one. So far in the few hundred miles I have driven since first firing it up last Satruday I hae not had a hint of detonation. I can lug it right down to 1000rpm in 4th and still pull cleanly, not a hint of pinging. After some more miles I a going to give middle grade gas a try.