Hello all,
I have a 1993 D250, 2WD, standard cab, and auto tranny

I have a 3 54 diff and of course its open diff.

I have removed my ABS. I am going to get a limitied slip gears. Would like to know if anybody has installed a 3 23 or 3 07 gears.

I currently get approx 18 MPG, and would like better MPG, I dont pull or haul anything.

Any and all comments will be greatly appreciated.

Brad

 

I don't think a 3:23 gear is made for the dana 70's or at least I didn't find one listed on a couple of sites I checked at before posting.

The 3:07's use a different axle housing than the one you have. I do not know if a 3:07 carrier and a 3:54 carrier interchange. Untill I get my hands on a 3:54 carrier to compare to my spare 3:07 carrier I am going to say they are different. I know Dodge lists both carriers with different part numbers.

An OD and 3:07's make good road gears. At 60 MPH your looking at 1650 RPM compared to your 1900 or so RPM. The down side is the cost of the swap to a 3:07 axle would take a while to pay for itself in fuel milage. Thats after you find one. They are getting hard to find and bring top dollar most of the time. Dodge was the only one that used that gearing. There is no aftermarket support for the R&P and Dodge has been N/A for about 5 years now.

 

You can do some engine/tranny tuning and injector/turbo/pump upgrades and get low 20s for less than the cost of a 3.07 swap and rebuild.

Have you checked your valve adjustment?
Timing? Verify with a gauge, and dont rely on the timing pin for TDC.
INjector and pump condition will also hurt MPGs.

Your biggest MPG loser is your auto tranny, and higher gears wouldnt help that.