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D13 · 03-23-2011, 07:24 AM

3.42's in 14bolt SF, 8 bolt 16/16.5, any light 3/4 ton. That's how the 81 above was set up, and I could make it get 15's pretty easily. Taller tires would help, I was running about 31's.

3.23's were an option but rare.

Clifford will hurt your mpg (it's more of an RPM manifold) but the headers should help slightly.

It's those rear gears that are the killer. Which axle do you have, 12 bolt or Eaton?

03-23-2011, 07:24 AM	#33
D13 Registered User Join Date: Feb 2007 Location: Memphis MI Posts: 1,851	Re: Better gas mileage 3.42's in 14bolt SF, 8 bolt 16/16.5, any light 3/4 ton. That's how the 81 above was set up, and I could make it get 15's pretty easily. Taller tires would help, I was running about 31's. 3.23's were an option but rare. Clifford will hurt your mpg (it's more of an RPM manifold) but the headers should help slightly. It's those rear gears that are the killer. Which axle do you have, 12 bolt or Eaton? __________________ 1987 2 ton 1982 250/TH350 beater in progress Dad's 1981 3/4 L6 3 on tree posi and no options, awaiting restoration or scrapping Plus a mess o' tractors Last edited by D13; 03-23-2011 at 07:28 AM.