1959 Carb adjust

[Bruce L. Wiley]

My 56 apparently has a carter carb from a 59. It has the two outer adjustment screws and one big one in the middle. Whats the best way to adjust this?

[Tim Lewis]

The large screw is an air bleed, used to adjust idle speed. You may have noticed there is no idle speed screw on the throttle linkage.

The 2 smaller screws fine tune the idle mixture.  
I dont have the factory manual with me at the moment, but  genericly:

Engine warm, idling,
Adjust the large screw to get desired idle speed, then turn each mixture screw in slowly until engine begins to slow or misfire. Turn mixture screw out 1/2 to 3/4 turn.
You may have to go through all the steps a couple of times to get the best setting.
Put it drive, make sure it is idling fast enough so it wont stall.
I dont adjust it in gear unless someone is holding the brake, just for safety.