85 Chev C10, 2 wheel drive, 350 cid, 4 brl Edlebrock carb, 350 turbo A/T 348 diff ratio. QUESTION.. what is the best rear end ratio for pulling a 7000# camper? The truck has had all polution and computer disabled and a 78 HEI distributor installed. How can I get the best gas mileage? What is the easiest way to install a 40 gal or larger gas tank?
I'm not sure what would be best for your setup, but generally lower gears (like 4.10's or 4.56's) would be better for towing, but they aren't going to help your gas mileage. If all you do with this truck is towing, then I personally wouldn't worry much about mpg. If you use it as a daily driver and do a fair amount of highway driving, then you may want to look at getting a 700r4. The easiest way to get 40gal of fuel would probably be to do dual 20gal saddle tanks like they do from the factory, but some people have put suburban and blazer tanks where the spare tire is on pickups; (Burbs had an optional 40gal tank), but this does require some fabrication and new cross members, as well as coming up with a way to route the filler neck.