Too Much Pinion?

I’m running a 3 inch drive line with 1350’s on both sides in my Duster. Have had both a 742 and 489 cases in. (different ratios in each) both with adjustable snubbers and no issues.

Even with the rear drooping, you should be able to spin the tires and axle smoothly.

What else did you change while having the pig rebuilt? You change axel bearings? Brake job?

As the other guys said, check the pinion angle.