Repair-It

It was starting to scream. Narrowed it down to the fixed idler pulley in the middle. It wasn't super loose but seemed dry. So I ordered this handy kit from Gates:
https://www.rockauto.com/?carcode=13541 ... type=11659

Looks to be a cake job.

Not quite as cake as envisioned but close. Also it was cold and I wore shorts for some reason. The only "trick" was I had to unbolt the ignition coil and hinge it out of the way because the tensioner was actually held to a bracket with a nut on the back.
Routing the belt also didn't require threading around the fan due to the way it was routed, which was nice. The old belt didn't even look that bad but the noise is gone and this should last the rest of the life of the truck...