Well I have my 94 idi turbo with the junk dana 50 ttb and the 10.25 rear end. Now I have 3:55 gears and my fuel milage is amazing around 17 mpg. But I recently found a deal I can't turn down for the same axles but out of a 89 f250 and with 4:11 gears I know my milage will drop but does anyone know how bad ? And the guy told me the axle has the speed sensor about the ring gear like mine so this should work right ?

 

I have a 86 6.9 turbo zf5 speed so gle cab with 4.10s and I get like 12ish in the winter and in the summer I had to many problems to get a accurate number. But I could go about 220 miles on one tank which would be about 15mpgs. If you are on the highway 4.10s suck. 65 is about all I can do without raving the **** out of it. But I can move a mountain with that gearing. Im looking to get 3.55s what is your rmps at 70mph?

 

At 70 about 2200 -2300

 

what kind of transmission do u have standard or auto? I have a 92 7.3 with a 5spd and get 18 mpg at 70mph with car trailer and car on trailer with 4.11's with 33's

 

Piece of **** e4od but it abd the trabsfercase were just completely rebuilt 12k miles ago