Does the OP know someone with a known good carb they could try, already running on something. Don't jack with it, just install it, fire it off and see if it acts the same way.
I thought that was a 4150-4160 carb. Doh! It's one of those motorcraft copy carbs, friend had one many years ago when summit first started selling them, a trash can would have been a better carb.
Run the float level down half a turn, see if that helps. That cam is so small, you shouldn't have to dick with anything on the carb to get it running. 12-14 initial and it should idle smoothly around 700-800 easily.
Something, somewhere is royally F'd up.
Trigger wires from distributor reversed?
I tried... good luck.