How much can a 454 head such as the 049 be milled? And approx how much is the volume reduced per .001 milled? thanks cc  

My 049 heads, with 2.19-1.88 valves had .020 cut, and ended up with 118cc. Bigger valve displacement, as well as the fact they were no longer "sunk", made 118 possible. Chanbers were originaly 121-122cc's. Made all of them 122, and made the cut. You can angle mill and reduce chamber volume further.