Does anyone know what the compression ratio would be for a 79 460 with flat tops and 73 heads. I was thinking about shaving the heads and I didn't know how far I could go before making my compression too high.

 

You should have 97cc heads. Every piston maker will be a little different. Look up their piston compression with a 97cc head and they shuld tell you.
A rough guess would be 9.5 to 1 which is getting about as high as you would want on pump gas.
Jimmy

 

Be cautious in milling your heads. For much more than cleanup you'll have to have the intake manifold milled for alignment. Pistons are a much better way to achieve c/r.