What model truck do you have and what tranny and rear end?

 

For what it is worth, I got 11.9 driving a 79 F250 2 wheel drive form Ft Bragg NC to Ft Worth, TX. doing my best to drive at 55. (And no, no one ran over me on I20). Stock 460, C6, 4.10, 235X16

 

Can you provide a list of "to do's" that you have personally found successful in improving gas mileage on a 460?

Thank you!
Ken

 

Get rid of that emissions Holley carb and replace it with a Holley 1850 or any other 600 CFM vacuum secondary carb that meters fuel rather than air. Change the power valve to a 85 or if you are towing with it too, a dual stage power valve. Get a distributor with a shorter advance curve, 10° preferred but 13° or 15° will work. Get an adjustable vacuum advance can for the dist. Total mechanical advance @ 36°. A dual exhaust system (2 1/4 or 2 1/2") or a single exhaust with at least a 3" pipe but 4" is preferred. And the biggest help is to slow down. I found that with my 1984 F250XLT Supercab, Superduty, 460, C6. 4.10 and stock tires had the mpg drop like hell after 58 mph, so 55 is a good place to stay. I also found that the cruise control did as good as I could using my foot.

 

Wow this is an old thread reserected from 2006.

 

That just means he used the "SEARCH" button!
I had a 1977 F250 2wd,460,C6,Dana 61 with 3.07 gears and got consistant 14mpg....but I used a Quadrajet instead of the holley,edelbrock,or motorcraft 4350.... and that truck drove sooo smooth and passed emissions here in California w/o problem.