I was hoping someone could help me out? I have a 71 3/4 ton long bed fleetside 350 2 bbl auto 4.11 rear with 16.5 tires . I only get around 7 mpg highway and was wondering what model year rear ends would fit in my truck (ring/pinion) or possibly swapping out the entire rear. 308's ? I was seriously thinking of swapping the entire driveline over to a 1/2 ton as I would have a larger wheel selection plus I thought I would have a better ride. But after reading some of the other peoples comments I don't know now. I do in fact need to somehow increase my gas mileage as I want to use it as a daily driver. It's a Ca truck with 79000 original miles and I have it sitting in my yard covered up as I can't afford to drive it. Any suggestions? Thanx Mike
3/4 ton gear Hello Mike. I also drive a 3/4 C20 fleetside with a 411 gear and 16,5 tires and drive it on LP Gas doing about 8/9 mpg. not driving it over 65/70 mls per our,if you drive it faster you feel like driving a race car,and than it start to take more gas,a lot more. I was thinking about buying a overdrive gearbox ,the one that's build right behind the th400 automatic,so when you doing highway cruisin (65/70 mls) you just push a button and the rpm dropes like 600/700 rpm.when doing 65/70 mls per our So maybe this is something for your Pick Up to,the only problem is the pricetag of thies overdrive boxes,they are rather expencive. Ps. I believe that Car craft or Hotrod dit an artikel on those boxes. greetings from Holland (Europe) Nico.
