1974 Duster Idler arm question,

YES (I see a problem) Post a photo please. At least one (both) of the brackets on the car "bend." This means that if the idler is properly built AND COMPLETE, the bolt will properly tighten up the mounting sleeve. WITH THAT DONE there should be very little up down movement.

Just how much "of that" movement is there? 1/8? 1/4? More?

I thought the play was about 1 in. but its more like a 1/8 to a 1/4 in. If you notice two of the bushings are missing and a top and bottom washer.