406 with D1SC, very good heads, etc made 14 psi at about 6400 rpm with a 3.85" pulley. Each 1/8" in pulley size is approximately one psi of boost. In this case a 4.75" pulley should be close to 7 psi or so.
Realize there are many variables that will change the above. Airflow through the engine, cam, exhaust system, etc. will all change these numbers. That's my best guess, or "shot in the dark".
Jody
|