Russ i feel your frustration. Long story short i bought my MK beam secondhand but unused.
I went for it because it was the supra diff version and i was running a supra diff with fitting kit in a standard beam. So happy days i thought nice upgrade...
Of course I got it off ebay & a fair price to.... Now it was sold as 2wd and muggins here being a trusting fellow took the guy at his word. The key thing I didn't know is theres a difference between 2wd and 4wd trailing arms with the hub mountings being different thicknesses. I looked at it and thought that looks great and handed over my hard earned. You guessed it my new beam had one saph 2wd arm and one saph 4wd arm. Most peculiar and no major issue except this was not apparent until I'd spent 3 days at a mates garage fitting it all up with new coilovers all round. Messing about with new/old style beam bushes in and out to get floor clearance. Eventually get wheels on and of course 4wd side is sticking out.. head scratch wtf and the penny dropped... maybe not such a fair price after all.
low loaded back to my house. Stick in garage shut door and sulked for a bit. That was June. Now I have been waiting the thick end of 6 months for Anembo to convert a fresh pair of arms for me. I have my fingers toes and eyes crossed that it all lines up okay with the new trailing arms and the geo is good.
Trying to make improvements to the car gets so frustrating when it bites you in the arse. I heard good things about the 6 degree beams and I am hoping the car will drive better than ever when done but its way off plan so far.

Mark V8 - Love that spacer kit. If you do anymore spacer sets for the beam bushes i would be happy to purchase some from you.