gleefully stolen from another website:
On the genuine Carter AFB's used by Studebaker (not the ones for the airbox, different story):
(1) accelerator pump shaft seal was accomplished by adding a brass fitting with a cavity inside the airhorn. The accelerator pump shaft ran through the cavity and had two teflon washers, one on either side of the cavity, held in place with a spring. The shaft ran through the bottom of the cavity, washer, spring, washer, top of cavity.
(2) the idle mixture screws were sealed by milling a cavity into the body around the screw, into which was pressed an O-ring, with the idle mixture screw going through the O-ring. The O-ring was held in place by a steel washer which in turn was held in place by the idle mixture screw spring.
(3) the throttle shafts were sealed by milling a groove around each throttle shaft inboard of where the shaft exited the carburetor body. Distance was maybe 3/8 inch. Don't remember exactly, and not critical for this discussion. Grooves were then milled in the carburetor body intersecting the grooves in the thottle shafts and going to a low pressure area by the outboard edges of the secondary air valve area. Thus the seal was actually a vacuum seal, as the pressure inside the groove was less than in the throttle area.
Carter also placed aluminum baffles inside the brass floats, but the stock floats without the baffles seem to be good for up to 5 pounds boost. We had MUCH better luck with the baffled brass floats than the phenolic. The pressure caused the phenolic floats to absorb fuel and become heavy.
Also, if the pressure gets above 4~5 pounds, you will have to boost reference the fuel pump rather than atmosphere reference, so the pump can pump fuel into the carburetor.
No further explanation on how you worked around all the problems you had.
