The Stovebolt Site Forums The Shop Area General Truck Talk Tuning Edelbrock Carb

I need to retune my 4 barrel edelbrock carb, it is currently tuned for Kansas altitude, and I live in colorado. . . will I need to just rejet it?

Depending on how much altitude change you've made, you'll probably need to go several thousandths smaller on the main jets, probably only on the primary barrels. The secondaries can stay a little rich to combat high speed lean-out and the accompanying danger of burning holes in the pistons at wide open throttle. Let the condition of the spark plugs be your guide. A properly-jetted carb will result in the plugs running from a light tan to a chocolate brown color under normal operating conditions. White plug electrodes, and/or a glassy, blistery appearance is too lean, dark brown to black and sooty indicates too rich. The screw adjustments at the front of the carb are just for idle smoothness, they have nothing at all to do with cruise mixture. Changing the metering rods and/or vacuum piston springs will alter throttle response and midrange performance, not overall mixture. Good luck!
Jerry