[SCOTI]

Originally Posted by aggie91

It appears from my research that the LOWER ball joint is the same from 1971-1986 ('87 R10 also). But the UPPER ball joint is specific to the 71-72 and then a different one for the 73-87.

Thanks. That makes sense. The upper BJ & the TRE's were the changes.

I would think that mounting the UPPER ball joint to the underside of the upper arm will give you a slight increase in ball joint height (it moves the pivot point of the ball about 1/2" to 5/8") vertically referenced to the plane of the arm. I my head, that tells me you would get some benefit similar to a taller ball joint...

I bolted the uppers under the a-arm before I knew 'tall' BJ's were available.