Well everybody I finally found the number for the O/pressure sending unit from Cummins. The cost on this is 73 bucks as apposed to 173.00 bucks .
Cummins pt# 4921511
By the way this is a relatively easy to change . The tools required are a 32MM deep well socket or a 1.250 socket, and a rachet .
You can see the sending unit from the inner fender well just aft of the shock tower. You can also reach it with a long extension too. But you will still have to reach down past the air horn to start the unit.