Thanks. It's amazing how strong that plate is even when it's heated cherry red. I'm glad I rented a plasma cutter to cut it! I didn't even have to use an internal tube to stop the new bracket from collapsing the factory crossmember at the new bolt hole I drilled near the torsion bar socket when it was tightened. It clamped the crossmember extremely hard, but didn't even begin to crush it. the new bracket just wouldn't yield, especially in that area so close to the torsion socket, so I skipped it.
The addition of a rather stout cable-style, shifter-mount welded solidly to the top plate I added to strengthen the torsion bar crossmember on the inside the car, and welded along the transmission tunnel back to the rear factory console brackets should help stabilize the factory torsion bar crossmember even more.
I was initially thinking of triangulating the sub-frame connectors to the torsion bar crossmember, but it is so much stronger now than when I started, I decided not to bother.