Back in the 90's I was daily driving a 64 300. I had just parked the car when the adjuster let go. The threads in the swivel tore out. At the time there was a mopar specific junkyard in Tucson that I got one from. Drove it for another 10 years without issue.

2196750 and 259651 are the left and right anchor package part numbers, remember one is RHT the other is LHT