IT has to be my stock pump

Nice day so fire up the Dart for a warm up,well after having problems with my 3310-2 flooding i blamed it:banghead: so i put my 600 on it a wile back.Well It is doing the same dam thing again flooding after it is shut off,the pump must be building to much pressure blowing the needle and seat wide open when i removed the fuel line at the carb fuel gush out, but i mean big time like it was a garden hose turned on full blast.Share your thoughts.