I put my front end back together on my 1966 Mustang yesterday and had a couple parts left over...lol After some research it think they are steering arm stops that bolt onto the lower control arm. Can anyone confirm this? Does anyone know exactly how they go on

 

Not likely, the strut rods have stops formed in the ends during manufacture. Post a photo.

 

 

The 65-66 has a steering stop bracket. From 67 on they were built into the strut rod

 

My mistake for taking the illustration catalog as gospel (it shows from 66 out with a turned up Strut rod). Anyway it looks like you got your answer in 2+2's photo. good luck.