Aaaaackkk, I feel like an idiot. Never can be too thorough.
The knock was indeed something popping back into place. My lower control arm popping approx 2mm back up my ball joint! My two outer ball joint bolts are backing out on both sides, even with proper TQ and new lock washers. I have used thread lock now-if that doesn

Gland nut,bumper stop etc all good. I installed new ball-joints and control arm bushings 6 months ago.
Yes it is the original 29 yr old stock steering sys. I'll verify gripe and post results. Your time is appreciated.

I guarantee its the idler, bounce the car with the bonnet up and watch it move around.

your quick dodgeman!

Grab the idler arm itself & give it a shake. Failure of the original bushes after thirty something years is rare, but not unknown, which is why several companies make urethane replacement bushes for them.

If your shock absorbers have been replaced with cartridge inserts, then make sure that the gland nut at the top of the strut tube is tight. It should be accessable by just jacking up that side of the car. Most times you can even leave the wheel on.

If this nut is loose, the shock insert can rattle up & down in the tube making terrible noises. Tightening it is a very low cost fix.

Sorry to be long-winded.
I