Hi all. I recently bought a 90 cummins 350 dually with the 3 speed auto. It has the 3.07 gears in the rear. I couldn't stand driving the auto especially with no overdrive, so I put in a getrag 360. I got all the parts from a guy that works on these machines a lot, and the conversion was pretty simple. However, my speedometer and odometer is way off now and tends to only work occassionally. I put a new speed sensor on, but no luck. I used the sending unit off of the 727, because the plug was different on the 360 that I got. Does anyone know if I have to get my pcm flashed or anything. Or do I need to find another sending unit? Thanks for all your help.

 

you should ask cummins forum they could probably help you better

https://dodgeforum.com/forum/dodge-cummins-diesel-88/