The milling job you're describing has already been done for you- - - -just use an 848 casting number head. Chevy raised the compression that way starting in 1956, I believe. Recessing the valve doesn't present a problem because the flat part of the head where the intake sits is milled away, so no shrouding happens. Yes, it's necessary to trim the intake stems to maintain proper geometry with the recessed stems. Do yourself a favor and fit some 1.6" diameter exhaust valves, and pocket port the head to accommodate the bigger valves. They're identical to small block V8 exhaust valves, so they're plentiful and cheap.
You won't raise the compression two ratios by milling .100"- - - -whomever told you that was ignorant or a liar. If you've got much over stock lift on the intake valve lobe of the cam, consider flycutting the top of the piston a little to assure you don't get valve-to-piston contact. A .030" thick solid copper head gasket used to be available to stovebolt hotrodders- - - -not sure if it's still being made.
Jerry
Last edited by Hotrod Lincoln; 01/31/2014 4:56 AM.
