Sgl or dbl brl carb?

[68gmsee]

Originally Posted by Poppateez

Getting 10mpg; would love 15mpg; which way do I go? straight 6 / 250.

Changing the carb to a 2 barrel may not get you better gas mileage unless yours is bad. There are a lot of other mechanical and ignition problems that can cause low gas mileage. As mentioned above, one thing is rear axle ratio but engine condition like worn rings, valves, cam can also affect mileage.

It could be one or several things involved. What I would do is to start with the simplest thing first. Replace all the ignition components like distributor cap and rotor, points, condenser, plug wires and plugs themselves. Maybe even the coil. After that get a kit and rebuild the carb. They're very easy to work on.

If that doesn't help, you're looking at engine rebuild or rear axle swap. I get about 15-16 mpg on my GMC 250 with single barrel and 3.54 rear axle.

[pritch]

Originally Posted by 68gmsee

I get about 15-16 mpg on my GMC 250 with single barrel and 3.54 rear axle.

Yeah, that's about right where I am. 250/4 speed. Not real sure about my gears, either, I used to think 3.73, but I think maybe 3.54 seems more realistic with my mileage and the fact that I can do 70+ all day long on the flat.

[Poppateez]

Pritch thanks for your input.