carbed out

Hope everyone is well, need some carb advice, ihave 73 dart with 273 , pro comp intake(faux airgap) unknown cam, 13.5" vacuum , had edelbrock 1400 carb on it after a year of jetting,rodding just couldn't get bog out of it , i am running 15 degrees advance,without vacuum hooked up ,34 degrees at 2800 rpm bog got better but couldn't mash the gas , so i bought a rebuilt holley 670 avenger at carlisle from a vendor,fouled my plugs after 5 minute idle , adjust floats,then carb floode out of front vent , float full of fuel,bought new float,back fire out the carb and mix screws make no change in rpm? pulled front bowl, took out power valve to test ,ok but gasket in two pieces top and bottom? picked up 5.5 power valve and install test carb fouled plugs again,and mix screws worked for first minute then no change when adjusting, checked primaries and secondary for closure and transfer slots closed with no idle screw adjustment , the vendor has full message on recorder and can't leave a message (should have known better) i seem to be getting fuel with idle screw backed out and butterflies closed ? power valve gasket problem? carb no good? any reccomendations for carbs demon ,holley has to be an easier way thanks for info , i want to drop kick these two carbs