440 six pack high idle

It's very very simple in theory, maybe not so easy to find. An engine HAS to have air to run. If you kill the air, "it won't." ^^As above^^ and look everything over carefully. Vacuum leaks, carb gaskets, all throttle blades, vacuum hoses, leaks at the intake--to head, missing plugs, EVEN A CRACKED INTAKE

If you are about to give up, pull the outer carbs, make block off "gaskets such as pepsi can pieces, and set the carbs back down to seal them off, leaving only the center carb