My set up looked just like the pics of
tlm47201 I almost think this is the thread I built them after.
I bought the tubes at Harbor Freight and am now wondering if the are 2.25" or 2". If I recall the issue correctly the lift tubes are taller then they are wide. Maybe bad machining on my part but the adapter just seemed real sloppy when it was finished. I also recall very little tolerance between the bumper and adapter once pined (i used the lft ring pins not 1" bolts). If the lift tubes were bent sideways at all mine would not work.
I guess my overall advice to anyone designing this set up would be to ensure close tolerances, shims if need be, and have a way to bend the lift tubes if they are bent at all.