The only difference that I can think of is the adjuster sleeve. The early cars it is about 1" longer, but the hole and taper is the same on the center link and steering arm.
Rockauto lists the same adjuster sleeves for 68 and 71, yet the 68 tie rod ends are 3x as expensive. The tie rod ends the bigblockdart link suggest you to get are the more expensive ones and the link says they work for nearly every A body other than the early Valiants.
I think you're safe going with the cheaper ones as far as them fitting correctly. The quality of them is a toss up though.
