Well i now work at a very good and well known 4x4 shop and was talking the other day with the shop forman about my speedo and 4.56s and 35s and he said that if it has a NP231 t-case then just buy a speedo gear that we sell for the jeeps and that will fix it ! Just figured somebody could use this instead of spending $300 on a programmer when the plastic gear is like only $30 !

 

That will work on the 97 and older trucks. 98 and up, programmer is about the only option.