What is the proper way of adjusting the idle mixture on my '72 F100 302 2V? Can I use a vacuum gauge? If so do I use manifold vacuum or carb vacuum? Thanks

 

You can use a vacuum guage on the manifold, but you can adjust it by ear too. Get it warmed up so it will idle slow. Pick one side and turn the screw in till it runs rough, then back it out till it runs the best. Then do the other side the same way. Then go back and do the first side again, turning it in till the engine just starts running rough, then back the screw out till it clears up, then turn it out 1/4 of a turn more. Then do the other side the same way.