Ball joint socket size and where to purchase?
Per the service manual, you need to be able to torque the ball joint to a minimum of 125 ft-lbs. If you can't get it to do that, time for a few spot welds. It's not a bad idea anyway. If this is a hobby car and not a daily driver, with regular greasing the new ball joints should last forever.
This is from a 1965 manual I downloaded from mymopar.com
You'll notice it says to replace the control arms if you can't get the 125 ft-lbs. That's what the tack welds are for. As long as the control arms aren't bent, rusted or cracked to the point of having lost their integrity, you'll be good.
Per the service manual, you need to be able to torque the ball joint to a minimum of 125 ft-lbs. If you can't get it to do that, time for a few spot welds. It's not a bad idea anyway. If this is a hobby car and not a daily driver, with regular greasing the new ball joints should last forever.
This is from a 1965 manual I downloaded from mymopar.com
You'll notice it says to replace the control arms if you can't get the 125 ft-lbs. That's what the tack welds are for. As long as the control arms aren't bent, rusted or cracked to the point of having lost their integrity, you'll be good.