74 duster lca bolts/studs?? replace?

If you are talking about the large nut that holds the lower control arm (lca) to the K frame, that stud is pressed into the lower control arm bushing (which is rubber) and then bolted in with a 15/16 or 7/8 nut and lock washer. When you try to remove it, it is very common for the stud to break loose and turn inside the worn rubber bushing which would imitate a "stripped" bolt. You will not be able to remove the bolt.

I usually heat the old bushing with a torch and let the rubber burn for a few minutes to soften it up. Then you can remove the torsion bar clip, release the tension on the bar, then pry the lower control arm back with a crowbar (which will also remove the torsion bar) The stud will pull out of the old lca bushing and stay attached to the K frame when the lca is removed..

After the lower control arm & torsion bar is out of the way, you can hold the LCA stud with a pipe wrench and remove the nut and washer. Clean it up on a wire wheel and press it into the new LCA bushing and re install it!