Early vs Later Upper Control Arm Fitment

[basstrix]

Are there any known fitment issues with using the earlier style 4-bolt ball joint, vs the style used on 71-73's that only have 3 bolts? The "nose" area around the ball joint looks to be more blunt on the early version. The later version looks to provide more clearance...perhaps with the spindle or backing plate.

The reason I ask is several years ago I bought a front end kit from a guy on this site and didn't notice the UCA's were the early style. I'm not concerned with difference in form-factor as long as fit and function are compatible.

On the left is the 71-73 version, right is the earlier version.

 

[Hemikiller]

Our 71 XR7 had the four bolt upper arms on it when we bought it. I changed from 15X7 to 15X8 Magnums to when I bought new tires and the inside of the wheel would grind on the edge of the arm. Looks like the PO had trimmed the arm to clear the 15X7 that were on there. Swapped to the 3-bolt 70-73 arms and no more issues.

 

[basstrix]

Thanks Hemi, that's exactly the kind of info I'm interested in.

 

[basstrix]

The attached pdf compares 3 different Upper Control Arms. One is the 3-bolt version, used on our cars, and the other two are different styles of earlier version, 4-bolt (ball joint). The 3-bolt provides the most clearance, but I found it interesting that there are differences in the 4-bolt designs. It's possible the intermediate version was modified, but, I was able to find similar profiles on the internet (see the first post in this thread).