pinion angle, how to change it?

[Jeff Chambers]

I don't think I'd recommend drilling different mounting holes for the uppers or lowers, especially the uppers. There's not much extra room to redrill the holes and the bushings wouldn't end up getting the support laterally that they need. The upper & lower mounting points are both weak points in the rear suspension so any extra drilling or cutting is only going to weaken them further. If you are dead-set on this approach, you'd want to move the front mounting holes for the lowers more rearward, essentially pushing the bottom of the axle backward which would pivot the pinion lower for a more negative angle. But again, I wouldn't recommend it. UPR makes a set of double-adjustable uppers that are pretty affordable and would give you all the pinion angle adjustability that you'd need.