hi. do you set air screw on a 276 the same as a monoblock turn in till seats and back out one and a half turns? and i have a 56RR i do not have the tt carb has a new monoblock but no numbers. i think it is a 376/1. the restoration book shows the 376/1 for an iron head. should i have the 376 or a 389? i am looking at a 389/31. thanks