holley 750hp carb on a 383. every now and then it stumbles when i floor it from a dead stop. where do i need to look. pump configuration is box stock. 18* initall timing. thanks Dave

im not where near an expert but i would try your float. thats what was wronge with my qjet.

on my 406 with 750 holley I had to go up several sizes on the accel pump discharge nozzle to get rid of my off idle flat spot. You can try a diff. pump cam also, although I didn't get much change with the diff cams, the bigger squirter did the trick