I'm having an issue and would like to get some other ideas. We built a 71 383/727 to install into a 72 Swinger with PS and PB. The engine is bored .030, 9.5 flat top pistons (cast), stock 906 heads (new valves, seats, 3 angle valve job) no port work. Edelbrock dual plane intake w/ 750 carb. The...