I just failed emissions. Suck! I passed with flying colors last year but I messed up my fuel filter threads and I had to buy a new carb. I bought a Holley Rebuilt Quadrajet (for my 76 350 4bl) that is supposed to be factory tuned. I had to adjust it a little to get it to run right. Anyway, I'm running way rich. Suprised me. I have no adjustment for reach/lean on the choke so I have to use the two screws in the front. My question is how far out should these be? Currently they are out 1 1/2 full turns. My old one was out 3 full turns. Some of you say the screws should be out three turns. Is that 3 full turns or 3 half turns equaling 1 1/2 turns.? I used a vacume guage and set it where I got the highest vacume. If I understand correctly you tighten the screws to make it run leaner. If the answer to the above questions is 3 full turns I should be running lean with 1 1/2 full turns. What else could it be if my screws are off? To paraphrase this. I'm running way rich. What do I have to do to get it to run way leaner.