Carb mixture setting

[stangsally]

Have 351w that has been one performanced out, 300 on motor with new 750 holley mech. Want to know if there is a tool that will give you the proper mixture settings. I know i was running to rich at some point, at idle at operating temp. i could see black smoke comming from my turn downs while idling and your eyes would water just standing behind the car, but since i have turned the mixtur screws out about a whole turn at idle now the smoke is gone but i don't want to run it to lean either running 11 1/2 --1 ratio so far i have no pinging or after run on acceleration or shut -off. rich is better than lean. Would hate to loose a $9000 motor due to wrong mixture setting. Would u advise just keep checking the plugs on each run to see if she is running to lean or to rich?.