Ideas for fuel mileage - underdrive pulley? electric fan?

[75Monza]

In the end I just gave up and acknowledged that fuel will be the costliest thing for my square and if I want MPG, commute in my Geo Metro or pull/haul everything with my 05 dodge diesel. Square is just my toy because I love driving it and the look on ricers faces when you beat them across the intersection smokin' 37's.Yeah, I never grew up, lol.

 

[Scrapman]

Depending on how much you want to spend on saving fuel....why not try Gear Vendors drive. Bolts onto a T400 and gives you six gears insteaD OF 3.

https://www.drivetrain.com/chevy-gm...ar-vendors-chevy-a-gm-3-speed-automatic-trans

 

[rt66paul]

You should move somewhere with mountains and only check the fuel mileage when driving downhill

 

[Dysco]

Replace/repair carb. Make sure plugs,wires, disributor, are all good and timing is right.
.373 would probably be a good smart decision. But as others said, a more efficient vehicle is a better option.

 

[Rickf]

Depending on how much you want to spend on saving fuel....why not try Gear Vendors drive. Bolts onto a T400 and gives you six gears insteaD OF 3.

https://www.drivetrain.com/chevy-gm...ar-vendors-chevy-a-gm-3-speed-automatic-trans

3.73 gears with a th400 in a 6 tire truck might not be the best option. I have a 55.1 with 6 tires and put a gear vendors behind a th400 with a 14 bolt & 4.10's. Just shorten the driveshaft and lengthen the speedo cable.

 

[roundhouse]

I’d get someone that’s an expert in carb tuning to go over it

Even better if they have a dyno
Or a O2 sensor to check the air fuel mixture while you’re driving

The clunk could be from the driveshaft slip joint being a little worn out

And taller tires might help
It has the same effect as changing axle gears and is a lot cheaper