You are running too much fuel pressure. Kick it back to 6-7 psi. Also, the carb may need to be tuned as far as the accelerator pump cam and squirters. What cam is in this thing again?

Tommy, is it possible that he is floating the valves at 4500 rpm? I know I had a million mile 302 once that had weak springs and would float around 4500 rshared_pm.