Carburetor is overflowing after car starts.

On a 1984 with a mechanical fuel pump and 4 barrel carburetor, how is the fuel pump delivering fuel if the engine is not running? It appears the original carburetor was a Holley model. I'm concerned perhaps that you have multiple vehicle modifications which make any suggestions and theory kind of a moot point -- because no one here could possibly know your set up. I'd suggest seeing a shop near you to find out what's going on. My gut is that your carburetor has problems, or a fuel supply issue if using something other than a mechanical fuel pump has problems. Modified vehicles are something that need hands on help. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops