I would imagine that with that lift you'd be getting accelerated wear on the u joints, but don't know if they changed the angle of attack on your differential when they did the lift to compensate. Speaking of the lift, the reason I speculate that they cut off your receiver as opposed to breaking off or rusted... No way that heavy gauge steel is going to rust off prior to anything else, and the load to break it off before snapping the welds...no way, I say. I think when they lifted the truck they had to cut it off to make the lift work. You described the receiver as going through the plate, if it was intact, that is...I'm assuming like cars of my era with the gas tank fill through a hinged license plate kind of deal. That's not normal, at all, and I'm also wondering if they eliminated the "drop" that the receiver would have from the frame to "normally" get it just below the bumper to where it is now. You may be a victim of an industrial grade 'Nip and Tuck" as it were..
All that being said, my envisioned solution would be to get a properly lengthened properly gauged piece of box steel, 2 pieces of sheet steel, piggy back downward from the existing receiver, welding to that and the cross member, dropping your new receiver below the bumper where is should be. Oh, and put the hitch pin holes in it. 😆 I got it at 250 out the door if you find the welder intrigued and up for the challenge of unf%cking what some idiot did to f%ck you
Guys like that love to bitch about the idiot that came before lol. Just dont mention your line of work. With a truck like that, he wont guess it, lol Camo pants wouldn't hurt.