The Carburetor Shop LLC
204 East 15th Street
Eldon, Missouri 65026
Carter AFB carburetors for use on Pontiacs.
Carter began production of the AFB carburetor in 1957. Up through the 1980 model year 505 different AFB carburetors were produced, in sizes from 400 CFM to 950 CFM. Most of these units were produced for O.E. (original equipment), including more than 50 different for use on Pontiacs. The exceptions (A.M. or aftermarket) were the competition series racing units (4748, 4759, 4760, 4761, and 4762) and the “super-quad” series (9400, 9410, 9500, 9501, 9510, 9511, 9625, 9626, 9627, 9635, 9636, 9637, 9750). With the super-quad series, the last 3 digits denote the CFM. One must be somewhat judicious in reading this as the numbers were coded. Example the 9500 is a 500 CFM with Chevrolet linkage, the 9501 is a 500 CFM with Chrysler linkage, the 9510 is a 500 CFM with Chevrolet linkage and an EGR port.
The entire competition series were calibrated for use on Chevrolet engines.
Of the super-quad series, the 9400, 9410, 9500, 9510, 9625, 9635, and 9750 were calibrated for Chevrolet engines; the 9501, 9511, 9626, and 9636 were calibrated for Chrysler engines; and the 9627 and 9637 were calibrated for Ford engines.
NOTE THAT NONE OF THESE AFTERMARKET CARBURETORS WERE CALIBRATED FOR PONTIACS! Carter offered O.E. carburetors for every possible Pontiac use, so there was no real need to offer an aftermarket unit calibrated for Pontiacs.
In the early 1980’s Carter was purchased by Federal Mogul. The O.E. carburetors were dropped; and the super-quad series was redesigned to be able to produce the units for less, and thus sell them for less. These carried the Carter name but were produced for Federal Mogul by Carter-Weber which became Weber-USA. Some additional numbers were assigned at this time. Please do not ask us questions about the 1981 and newer units as we will not use these units, and will not even attempt to answer questions concerning them.
Later, Federal Mogul sold the rights to the super-quad units to Edelbrock. Please do not ask questions concerning these units, as we will not use them and will not attempt to answer questions concerning them.
Considering the use of AFB carburetors on street Pontiacs: we recommend finding the original O.E. Pontiac units WHICH ARE CALIBRATED FOR PONTIACS at swap meets on Ebay or where-ever and rebuilding them. The AFB is probably the easiest 4-barrel to understand and rebuild; and by reading the Pontiac service manual, anyone is capable of rebuilding these units.
The following remarks apply to recalibration of the aftermarket AFB’s produced by CARTER, NOT THE LATER ONES. The Pontiac engine more approximates the Chrysler engine in fuel demand than the Chevrolet engine. If one MUST purchase one of the older Carter A.M. units, calibration for a Pontiac is much easier if one purchases one of the Chrysler units than the Chevrolet units, although the throttle linkage is all wrong. It is much easier to change the throttle linkage and have a unit that is fairly close than attempt to recalibrate the Chevrolet units.
For those of you who would use the Chevrolet units since they are much easier to find and less expensive: for best results on a Pontiac engine, one should change/modify/machine the idle tubes, idle airbleeds, step-up rods, step-up rod springs, secondary jets, and the secondary airvalve assembly. Of these, the secondary jets and step-up rod springs are readily available. The “strip-kits” sold by Carter contained rods, but the rods in the 10-201 kit ALL had a Chevrolet profile, not a Pontiac.
The O.E. carburetors for Pontiac were sold in sizes from about 525 CFM to 950 CFM. Today, since Carter is no longer producing these, and the collector market being what it is; only the units from 525 CFM to 610 CFM are readily available at low cost. The others are fairly pricey! If one needs more than 610 CFM on a Pontiac; it is cheaper to build a dual quad unit with the O.E. Pontiac carbs than to re-calibrate one newer carb and do it well.
For purely racing use (no street), the original Competition series carbs may be used. Since idle is of no concern the idle circuit will need no mods, simply adjust the idle high enough to idle off the main circuit. The secondary airvalve assembly will REQUIRE changing (if you intend to win any races!).