Loosen countershaft lever clamp screw. Take end play out of countershaft, and hold choke valve tightly closed. Take slack out of linkage by pressing countershaft lever towards closed position with gauge in place between choke lever and stop in piston housing. Hold in place and tighten clamp screw.
A. Hold choke valve tightly open.
B. Hold fast idle cam against stop on casting.
C. The clearance between lug on outer countershaft lever and stop on inner countershaft lever should be as listed on carb spec page.
TO ADJUST: Bend lug on outer countershaft lever.
With choke valve tightly closed, tighten fast idle adjusting screw (on high step of cam) until there is the clearance listed on carb spec sheet between throttle valve and bore of carburetor, side opposite idle port.
With throttle wide open there should be the clearance as listed on carb spec sheet between upper edge of choke valve and inner wall of air horn. To adjust, bend unloader lip on throttle shaft lever.
Q: No ID on these carbs but I believe they came off an early 60's Pontiac. Dual AFB's on Weiand manifold on a 1957 Chrysler 392 Hemi, probably the 325 hp model. See if what I see makes sense. First there are no chokes. The rear carb is primary and as the throttle begins to open at about half throttle the forward (secondary carb) linkage begins to open. I'm assuming the rear (primary carb) secondaries will begin to open from vacuum at that point. Then at about 3/4 throttle the vacuum secondaries on the front (secondary carb) begin to open as well. I don't know of a way to confirm the action of the vacuum secondaries. Does that sound right?
A: I belive that if there are no chokes, these are off a Chrysler. As for the secondary’s they are both mechanical and vacuum operated and it is a progressive type linkage.