73-87 Spindles on a 68: lower ball joint

[darcane]

A while ago I ordered a bunch of stuff from CPP including a set of 2.5" drop spindles which I am now installing on my 68 C10. The kits included upper and lower ball joints as well as outer tie rods and tie rod sleeve, and the spindles were labeled as being for the 73+ trucks. I don't have many miles on my old ball joints, so I decided to leave the lowers since I've always heard that they are the same as the 73+ ball joints.

Well, I've got the spindle on and the nut for the lower ball joint won't tighten far enough to get to the hole for the cotter pin. Hmm...

So, I compared my old spindle to my new one as well as the ball joints. Sure enough, the shaft on the new ball joint is about .25" longer and the bottom part of the spindle is thicker by the same amount. Otherwise the ball joints seem to be identical.

Is this normal for 73+ spindles on a '68? Or is this specific to these drop spindles I bought? I was hoping to avoid banging out those lowers...