Assuming this is for a car used on the street, try the street section: https://forums.maxperformanceinc.com...play.php?f=418

Hello -

Welcome to the site. You'll get a faster response to your question if you post it in the appropriate tech section of the forum. Go to this link, and scroll down to find the section you need. https://forums.maxperformanceinc.com/forums/

Hello, I have a stock 1973 455, 4br, I plan to replace the stock 4X Heads with 6X-4 heads from a 350. The 6X’s are getting reconditioned at the Machine shop including exhaust valves upgraded
to 1.77.
If the deck surfaces need no or minimal removal what CR can I expect to obtain?
If I choose to have deck surface milled how much milling will give me the maximum CR using 93 octane pump gas?
Also what cam would give me the best street able performance?
Thanks in advance