Float level is too high and or the fuel pressure is too high, Also there may be some particles of dirt getting into the carb and holding the needle and seat open. All are easy fixes.Some times at hard tap with a screw driver handle will fix the seating problem,
Robbie "It doesn't cost any more to go first class,,You just can't stay as long"
67 GT 500 #1590 "Shelly"
67 Chevy II nova "Sherry"
833 HP 542 CI Dart alum motor
'32 Ford Tudor Rod