The support plate is damaged. I will try to weld it.
I would avoid welding the damaged plate. Not that I doubt anyone welding skills, but as important as the plate is, I would recommend if you can find a used one, first. I would think a few members here would have one for sale.
If a person wants to gusset or reinforce a used plate, then I would be all for that.
Also, if you can find the parts for the F-body recall, then that would be a plus (not a requirement, but a plus).
The ball joint really has nothing to do with or is in the way of removing (or replacing) the plate.
When the weight of the car is not on the ball joint, check it for looseness. If
ANY play present to upper ball joint – then change that joint.
Chrysler used a couple of different size ball joint socket sizes. If you find one that mentions B or E-body, then you are good. The C-body and pickups use a larger size and the older A-body (I think) use a smaller size.
The socket is a square with rounded corners:
I have the measurements at home. A person can use a large Crescent wrench and/or large end wrenches, if you have one, but the ball joint socket works the best. The O’riellys auto parts store near me rents them out (no promise the parts store close to you has it).
The only thing this socket fits is Mopar ball joints, so it is silly to purchase one and use it once.
You will need a long breaker bar that is two-foot long (minimum) and three-foot long preferred. You will also need to loosen/remove ball joints with arms still attached to the car – for removing the joints off the car is, um, difficult. On the bench and with arm in a vice, you will find the work bench will start moving a long time before the ball joint starts to break loose (moves).
The specs say to tighten the ball joint until it bottoms out on arm, then tighten to 125 Ft/lbs. That said, it takes a lot more than 125 ft/lbs torque to loosen or remove most upper ball joints.
BudW