Update on my situation, it’s only been slightly resolved. After many different configurations with washers, I ended up doing the same stack of 2x washers per bolt on the bracket as OP
@phemer
This solved my immediate issue of the the belt getting shucked off the AC compressor in only a few miles. Since the compressor sits further aft now, it’s not in a spot where it’ll want to jump a groove.
The issue now is that the belt is riding way too far aft on then tensioner pulley, and the edge of the belt is slowly eroding and showing the fuzzy fibers.
After staring at this and poking at it with straight edges for hours, I’ve come to the conclusion that there may be 2 alignment issues.
1: When viewed from the top, my AC compressor is yawed to the left. Hard to tell by just looking but I’ve checked with straight edges and I’ve even outlined it in the attached photos
2: I believe that my entire AC amount bracket may also be slightly pitched upwards compared to everything port-side onwards from the crank pulley, but this is less serious than #1
Given that you can’t adjust these brackets, I’m really not sure what to do short of just starting to modify the brackets with some welding/grinding/drilling. I would like to avoid going down that route but I also can’t have these belts eroding after just 1500 miles.
My other thought was to just dump this Sanden compressor and its red dot afterthought bracketry, and move to the new style delphi compressor that’s found in the ECVs, REVs. The only thing I’m not sure of with that option is adapting the new style fittings to Eaton Aeroquip.