I guess I am being cheap, but I am trying to put a 312 together using what I already have and I need advice from somebody who is more knowledgeable than me. (which is just about everybody on here   The block has been zero decked and bored .040 and I am using ECZ-G heads, making my static compression ratio 10.3 if I am using the calculator right.  The cam I have has an intake closing of 39 ABDC, making the dynamic compression ratio 8.8. My question is, how much can the cam be retarded to reduce the DCR to a livable level for a street engine and not kill its power?  Should I bite the bullet and get another cam?  If so, recommendations?  The engine will be going in front of a Mustang 5 speed in a '46 Mercury coupe (about 3200 lbs).
Cam specs:
Lobe Center Line---Intake 106/Exhaust 110   Lobe Separation 108       Lift 454 with 1.53 rockers      Duration 226/226 @ .050    ( 259/259 @ .020)
Intake   Open 7 BTDC    Close39 ABDC              Exhaust   Open 43 ATDC   Close 3 ATDC
Thanks in advance for any help or advice.