[cadillac_al]

I get 11 mpg with a 350/350/np2o3 with 3.08 gears. I can't give up the 203 because I use it for bad weather. I have a 2wd for good weather and good roads. I think a 700r4 would be a very good swap for these trucks if you do a lot of highway driving. then again if you are doing lots of highway driving you may not need a np203. I would buy a tach first so you know exactly how high it is revving on the highway. It also matters how many miles you drive it per year. If you only use it for a couple thousand miles per year then the actual gas savings won't be so much.

The new Chevy 2wd trucks run 1500 rpm@70mph. I get 16 mpg at that speed. I don't think our old trucks can lug at 1500 smoothly. I think they could be happy at 1800-2000 cruising rpm.