Wayne put your glasess on and put the beer down. From the photos it is clearly low pinion 9.5'' diffs front and rear, pre 1990. Being a from a mine truck I would not worry to much about the year the vehicle is, as previously mentioned parts have been swapped around on the diffs you have. Looking at the rear it is from a later model than the front, see the difference in the webbing on the carrier housing. This could also mean the ratios are different front to back. Ie, they could be 4.11vs4.10
