edelbrock 600cfm

[dm300]

i have an edelbrock 600cfm on an inline six in a 78' f250 4x4. Has a 4 barrel dual plane intake and headers into dual exhaust. The carb was used about a month but it doesn't seem to be getting very good gas mileage at all. (under 10mpg) what jet size and or metering rods are good for this carb/setup? or is there something else i should try? thanks

[LxMan1]

Every combo is different. You need to read the spark plugs to see if they are black and burning rich. I would buy a calibration kit and play with the metering rods first. Larger rods = leaner mixture.
What else is done to the engine? Cam, headwork, etc. What trans and rear gear are you running?

[dm300]

Originally Posted by LxMan1

Every combo is different. You need to read the spark plugs to see if they are black and burning rich. I would buy a calibration kit and play with the metering rods first. Larger rods = leaner mixture.
What else is done to the engine? Cam, headwork, etc. What trans and rear gear are you running?

i looked at the spark plugs and it is black along the bottom of the threads and dark greyish or brownish on the tip. should it be more white? i listed all the mods done to the engine. would weak lifers affect the gas mileage? it have the np granny 4 speed.

[LxMan1]

Sounds a bit rich. Should probably be more of a tan/white color. Weak lifters should not effect the mileage much, just makes the cam act a little smaller if they are ticking.