2002 4.0 V6 4x4 "Bumping" issue?

[Mr.Wizard]

Hey guys, got an interesting problem and I'm wondering if anyone is familiar with it? I've got an original lower control arm lift on the front (Unsure of the brand but similar to the one rough country sells) and a body lift in the rear with 33x12.5 BFGs, appropriate offset rims - all tires are pretty new. I haven't re-aligned them yet if that's relevant. I blew my front right CV axle (likely due to the lift) and replaced them and all the sway bar stabilizer bushings, everything else on the front looked fine. I'm still having an odd symptom where it sounds like a decent size rock is stuck in one of the tires while I'm accelerating (And no, there is not a rock stuck in them). I can't pin down the location yet if it's front/rear or a certain side, it feels like driver but I'm unsure. I replaced the entire rear axle with a 120k B2000 setup awhile back after blowing out my rear diff offroading so while It's possible I think that mileage is a bit low for another rear diff issue. I've read that I still need to check the slip axle and U-clips on the drive shafts but the descriptions sound more severe in my case than what I've read up on - I did do a quick hand turn check for slop and both drive shafts seem sturdy. I've also read there's a pin of some sort in the rear diff that can work it's way loose and those symptoms sound more similar to mine but I'm yet to pull the diff cover and give it a look. The "bump" is definitely tied to the drive train spinning and increases with acceleration from low speed until you don't notice it as much at 35+. Has anyone had or heard of a similar problem and have any advice that I haven't covered when it comes to places to look?

 

[Uncle Gump]

I've never seen a lower control arm lift for an SLA equipped truck. The only thing it could be is reindexed torsion bar keys. Are you sure you only have a body lift in the rear? Body lifts are always under every body mount... both front and rear.

Probably the first thing I would do is pull the rear diff cover and have a look. Inspect for broken bits and metalic particles laying in the bottom. Inspect every gear tooth fir chips missing and ensure there is not a lot of slop. Is it a traction loc or open rear end?