Measure 5 times cut once.
Finally some progress.
Rear:
After looking at the 80 bumper and the 77 bumper, I decided it was not worth swapping on a new cross member. I notices there were 3 spotwelds on each body mount cup of the 80 bumper and decided to remove those. I am going to add plenty oof pictures for any of those who ever go this route. I apologize if it gets excessive.
The 79+ mounts are 2' 3 1/4" center to center.
78 and earlier are 2' 4 3/8"
I drilled out the mounts and cut out the frame with a die grinder and a hole saw to create the opening for the cups. The Hole for the cup to sit in is 1 1/2", but I do not recommend using that size whole saw. As you may know, these bits walk quite a bit. I used a 1" and opened it up with the die grinder. The 79+ cross members are significantly deeper to accomodate the mounting provisions.
Middle.
The Daystar bushings were kind of strange. The top bushing does not fit properly, but we were able to find a bronze gude at lowes and tractor supply that fit around it with the use of a Press. Now the upper and lower Bushing fit nicely together. once the tub is placed on the frame with the other two mounts, I will bolt the mount to the 80 frame wings that I sourced and use the body to actually align where these will be mounted and driilled for bolts.
Front (under cowl):
Thanks to the diagrams from the FSM. It seems as though the mounts are only 10 mm wider than the factory 77 holes. 1195 vs 1185. We drove over to Wimberly 4wd and took some measurements off a few 79-82. I knew that the under pillar mount angles upward on the new frames. This was hard to measure, but it looks to be 1/2-3/4. I plan to space this up with washers for now and make or buy a steel spacer to go in there once the measurements have been made.
The good news is that drilling the holes out went very well. We massaged the holes over 5mm and opened up the holes with the 1" hole saw. It turned out perfect for the new body bushings when mounted up.
Next trip down, I am going to put on the body and get everything welded and bolted up. Then I will remove the body and start the Monstalining and Epoxy Priming of the body.