After reading several posts, I am still questioning if I should add a lockwasher before the nut goes on. I see info about using loctite and I see year-one does not supply any washers with their arms and also the car did not have any originally.
I want to avoid things coming apart as well as avoid any squeaking. I am using original boxed arms, new nuts and bolts and have energy suspension bushings with supplied lubrication. 1968 Malibu. Suggestions? Thanks in Advance :cool:

I put flat washers aginst the frame so the nut and bolt are loading a larger area. The area that the bolt and nut contacted is distorted and the washer becomes a new contact area. I typicaly use a 1/2" SAE flat washer or an AN washer. The nuts should be a Grade C lock nut deformed end. Torque at 75 ft lbs with the wheels on the ground if using rubber bushings.

Thanks, I did find a new type of lock nut today at the part source auto store, it's got a slightly oval hole which apparently locks to the bolt quite well. I'll certainly be checking them all regardless...but some peace of mind is good. :D

I use the nylon insert lock nuts on my suspension bolts, and I have never had a problem in 8+ years...

The squashed looking nut is called a "prevailing torque" nut. That is what was used from the factory. Adding a washer might not be a bad idea, but you are also only loading through the diameter of the inner sleeve of the bushing.