In a panic, someone just told me I should have used 68 upper control arms on a 68 rear axel assembly that I put in my 66; because the position of the bushings on a 68 rear are 3/8" further forward than a 66 rear and if I use the 66 upper control arms the pinion angle will be screwed up.

Thought if I had a 66 frame I should use 66 upper control arms.

Is there really a difference in the position of the upper control arms bushings for a 66 and a 68 rear? Thought the only difference was width and spring perchs.

Jim, I found this post that I did a while back:

http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi/topic/28/6580.html?

and I found this on a 442 olds webpage:

http://www.442.com/oldsfaq/ofdif.htm
Check out the "Swapping" section near the bottom of the page.

I believe you are correct in using the 66 arms, but I think there still may be pinion angle problems because of the 3/8" difference in upper eye locations.

Maybe adjustable uppers could compensate for 3/8" difference?

Jeff
65 Chevelle

PS, I've found more info on rearend swaps on the Transmission & Differential forum, you may get more response by posting over there.

arms should match frame, not rear end