Ok when I first got the TB, I picked up both options of new belts to figure out which was the right one (unknown alternator mystery)
I learned that our trucks took the longer of the two belts.
Fast forward to my current project, I find (thanks donny) that the ext has a smaller power steering pulley. Yet the EXT shows the same belts, idlers, tensioners, etc...
So:
The belt # **** 915 belt is 92.125" long and fits the larger PS pulley (non-ext)
The belt # **** 905 belt is 90.875" long and fits the smaller PS pulley (ext)
Orielly shows this as 2 alternator options, but, autozone has them listed correctly as ext and non-ext.
Also...
Our pumps can be modified the same as the saginaw pumps as explained here: http://westtexasoffroad.homestead.com/p ... ering.html
This will give more steering force to the rack for those with larger tires. (do at your own risk of blown seals)