I finally got the frame welded up, and learned a few things.
1. My 110 MIG welder is barely good enough to weld 3/8" steel.
2. I suck at welding 3/8" steel with a 110 MIG welder...
3. Hair has a tendency to catch fire when you weld over head without a full face welding mask.
4. Red hot blobs of metal are drawn to open shirt sleeves like a tornado to a trailer park.
I used a spare 1941 Dodge generator bracket to gusset the frame down to the cross member. The test drive revealed no more wobble, and no more popping while turning sharp corners at low speed. I used a new Mopar (steering box to frame) bracket, and had a real fun time getting it all to bolt up. You kinda have to get one of the blind bolts in to the steering box (loosely), then wedge the whole mess up until the press in bolt on the bracket goes into the frame, stick a nut on that dude loosely, then feed all the other steering box bolts in, get them started, then push the other two frame bolts in, kinda tightening everything as you go. It took a couple of hours to get everything back in and safely tight.
I don't want to do that again for a while!
Mark