With the 3" relocation you shouldn't actually have to do anything to the end links. 72BBswinger used that bar, this is a picture of the mount and endlinks on his car
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I use the same rear bar on my Duster, but I don't have the spring relocation. On mine, because I used the stock frame rails I did the install similar to the instructions with the reinforcing tube through the frame rails. The bolts included with the Hellwig E-body bar are too short for the endlinks on the frame mount, the frame rails are actually wider on an A-body than and E-body where they mount. So I needed longer bolts. I don't remember buying new tubes, they were either long enough or I had the tubing on hand already. I used the supplied end links, but it does put a slight angle on the links because of the width of the bar. I made up a set of heim joint end links that will solve that issue, but I haven't installed them yet.