I have a 76 w200, with 400/2bbl/auto, which used to get 11mpg, if lucky. I got rid of the full-time 4wd front axle, by swapping in a part-time 4wd front axle, & put a kit into the transfer case to make it part-time, too. It gets 15mpg, now, which I can live with. It also helped the low speed handling, and reduced the turning circle.
