No sir. The UCA mounts are the same on all of them, 1963 all the way up to 1976.
So the issue isn't that the UCA mounts are spread apart or pulled together, it's that the width doesn't match the UCA. Are both sides the same?
The stock UCA's definitely flex more, but if both sides are the same and neither fits it seems to me that the UCA's are the wrong dimension. That can happen, they're welded on jigs and they aren't always perfect. Did the person you get them from actually run them? Or were they never installed?