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An excellent reference for setting up your Carter or Edelbrock AFB-style carburetor is Dave Emanuel's "Carter Carburetors" published by SA Design Books. However, for specific help in making these carburetors work well with in-line engines like Chrysler's slant six, I have had to do some research. While I was waiting for the parts to arrive so I could try using a QuadraJet on my Offy intake, I was also trying to get my AFB to run a bit better.

The problem I had been having was a bog off the line. I believe the problem was due to my lack of intake manifold heat because I was running headers previously and am now running Dutra Duals. When the throttle was quickly cracked open at low RPMs, the low vacuum and air flow caused the fuel to drop out of the air, thereby creating a lean condition. After trying the a number of metering rod and jet combinations from my Carter Strip Kit, I found that the metering rods with the largest difference between the economy step and the power step seem to work best. Since Federal Mogul is no longer making AFBs and Edelbrock has started making a new and improved AFB with the name Performer, I checked out their metering rods. Edelbrock has some metering rods with even larger differences between their economy and power steps so I tried the next size-difference larger. The performance of my car improved once again and the bog largely disappeared.

To completely eliminate remnants of the bog, there is a still a larger-difference rod available that I could have tried. I wanted to avoid increasing jet sizes because that would affect my cruising fuel economy and I think there is room to make the cruising fuel mixture a bit leaner.

After trying the Quadrajet manifold with the stock Chev 350 jetting and installing an intake manifold heater hot spot, I found that I had absolutely no bog on acceleration. If you are running a street engine, make sure your intake manifold heat control system is working properly before you try enriching your fuel mixture.

Another thing to try if you have the hood clearance is a carburetor spacer. Some people have found that they could eliminate their acceleration bog by raising their carb with the spacers that have separate holes for each barrel. The extra distance between the throttle plates and the intake manifold allows fuel to better mix with the air before it reaches the intake plenum. A carb spacer could also help to reduce percolation by better insulating the carburetor from the intake manifold. Keep hood clearance in mind as you experiment with carb spacers.