I bought a 66 chevelle, with it I got a box of front end parts, A complete disc set up, The correct set up. I bought lower front ball joints for a 66 and they were too small. So I bought another set and still too small. I set the arms next to a set I took off a 70 and they look Identical but are just a bit shorter. And the ball joint hole on the 70 is smaller. I blasted the arms and found no part numbers or stampings. I checked to see if a 69 camaro had a different ball joint and the parts list are the same. What are these from The rear of the arms use the same 2 round bushings one is biger same # as the 70. Any Ideas??????