Engine/Transmission (1998.5 - 2002) Speedometer adjuster module ?

[rootmanslim]

Many years ago I upgraded my 2001 2500 4x4 with Rixon wheles and big tires.

To correct the spedo etc I bought a little black box (not from superlift) to reset things (using a GPS). The other day the truck went nuts electronically (shuda kept my 12 valve!) and I'm trying to figure out where I might have bought this black box. Thanks.

 

[Road Dog]

Tire size is stored in the PCM and can be changed by any dealer and many engine programmers.