That is the top of your shock absorber. What makes it look like a roller is the rubber bushings that surround the bolt. It won't actually rotate without a lot of force but it will allow a little slippage.
Oh Rick, you are so sweet, a real doomsday pessimist, I am drawing the line somewhere, oh yes, BTW, I might, just might be able to get my hands on a 66 Fairlane, no engine/gearbox/diff, but all the rest I can have, trouble is is was said during a staff party so maybe once sobriety has dawned the offer may not stand. However if I do get it, what are the chances that some of the parts will fit my cougars, [idler arms etc], whatever I can't use of them I can use for the ranchero.