This is the rest of the idea. I mocked up a paper crossmember that I later transferred to CAD and had laser cut. I folded it and welded it up. Fits good and the loop from bolts to bolts is seamless like the OEM so no fear of a weld breaking and the tranny falling out.
This shows the isolator/mount I used
Paper Crosmember Mockup
Side view of paper trans crossmember from the side.