Idle's too fast

Need some please?
We have a 72 Ply Scamp, 318, automatic. Had a valve job done, converted to 4 barrel (500 CFM), ran good for a little bit, then one day I overfilled the fuel tank and discovered the seal was bad at the tank and filler tube area. Dropped the tank, cleaned and reinstalled, have a temp fuel line (from tank to fuel pump) because old ones clogged. Car started but has a very high idle. Rebuilt carb and I still have the same problem. I’m comfortable the carb is good, accelerator cable is not too tight, and everything else looks good. Any help would be greatly appreciated.