Now that I have two reinforcements/extensions in the frame rails, I need something to connect a receiver tube to. The factory bumper mounts were ~4.875" long so a length of 5x5x3/16 box tube was ordered to fill the gap and provide a decent structure without weighing a ton.
There was plenty of room height wise and I wanted to keep the receiver as high and forward as possible.
The master plan
Locations of the 2x3 box tube were laid out and then cut out with radius corners for a nice fit.
The 2x3 box tubes were run all the way through the 5x5 box tube for strength and the aforementioned clean out capability so crap doesn't get trapped and can get flushed/washed out.
Once tacked in place on the car, the whole assembly was removed and welded out on the bench, inside and out.
Ok, starting to come together now...just need to mount the bumper on the 5x5 box tube. The bumper is held on by M8x1.25 screws so 8 of these were drilled, pressed and perimeter welded. The bumper is a heavy awkward piece so I welded on some assembly tabs to generally locate it and allow some side/side movement if necessary. The up/down is fixed by the mounting holes and there's just no room to move it up/down.
The upper holes are not used due to the body lift and there being nothing behind them so they are used for the assembly tab. Just a slight lift and the bolts screw right in.
Similar situation at the bottom - two more bolts in the lower flange so it's more/less factory mounting, just shifted up a couple inches

. I had to do a little massaging to get a socket on the lower bolts.
After that it went pretty quick - Center and weld the receiver in with a chain loop, throw the bumper and bumper cover on and it's pretty much done except the wiring and some sort of finish (painting/plating - I don't know yet).
This is a 6" rise ball mount (borrowed from my other car) just clears the tailgate when swung open, but will hit for sure with a trailer attached so will likely end up with a 4" rise one.
That's all I did to my wagon this week - doesn't seem like much but is a big step in getting this thing on the road! Next week, figure out where/how I'm going to locate the trailer wiring connector and get that welded in, then take it all apart for paint/plate. Probably finish media blasting the frame/body behind the bumper and start painting. Between coats of paint I should be able to tear into the 8.5" 10 bolt and give it a good once over, replace all the bearings/seals/brake lines, etc and get it ready for installation.