96_12V

A friend of mine is considering a '96 2wd automatic with about 200k on it. It has the 4.10 rear end. He is wondering how much it takes (and how complicated and expensive it is) to go to a 3.55 rear end. Truck runs about 2250rpm at 70 mph. My 5-speed runs about 2050 rpm at the same speed. The 95 AT 4wd I owned for a short time ran at 1850rpm at 70 mph. He's more concerned about fuel mileage than pulling power, and as equipped and with a flat bed cover, the current owner of the truck gets only 18-19 mpg. Any thoughts?

BoostdCTD

There are several things you can do about fuel mileage, the easiest are put more air in the tires, drive slower, use less turbo when taking off, have the timing advanced, add an exhaust system and better air filter. The only way switching the rear end could be really justified as a cost save, IMHO, is to find another person who wants to swap and take it even up rather than buying new gears and such.

Crimedog

Browse around on the classifieds on here and at TDR. I was able to pick up a LSD for $270 complete axle minus brakes. Scan around on ebay, too. There should be some that show up eventually. For me it was worth buying the whole axle assembly versus paying $250 for just a used limited slip differential.