six barrel

Getting your air idle adj right can be interesting. Do you have the ProMax throttle plate for the rear carb? If not, how are you going to adj it? Getting the proper power valve for the center carb/jet size can be interesting. What color springs did you go with? What thermostat for engine temp? Ign timing? Air filter type? Fuel bowl levels. AFR for both sides of the engine, not just one. End carbs, start with 1/8 turn out to start, make sure that your needles are good, have not been overtightened and needles bent. All three carbs need to be in sync, they all idle together, not just the center carb. Every engine is different. I also run ProMax jettable plates instead of the metering plates on the end carbs. I was getting in the ball park last fall before winter came, will pick up where I left off in about a month or so. Never checked for fuel mileage, but 18 would be stellar in my book. My engine is a 418, will be slightly different, but not that much, they just draw a little harder.