If it is a Holley, screw your adjusting screws (on front of carb), not idle speed screw, all the way in. DONOT over tighten. Then screw back out 1 1/2 turns. If Edelbrock, 2 turns. This will be really close to perfect, just teek as needed to get perfect. A vacumn gauge is suppose to be used for best results, but I just go by ear.
I agree, little tan is best, not white or black.
Jack