[66sprint6]

I'm considering putting Bilsteins on the '67 LeMans. I've heard more positive than negative reviews on them, and their own site says that they work well with factory springs. We'll be replacing the springs as well of course, since they are original and worn out.
I was on their site and found the front shocks no problem. But they don't show rears for a '67 Pontiac A-body. I found this strange. Why wouldn't they have a complimenting shock for the rear. So I do what I always do, which is to input a Chevelle into the search box. Sure enough, there they are for a '67 Chevelle. I wasn't aware that there would be a difference between the Pontiac and Chevy rear ends. Is there a difference that would prevent me from using the rear ones spec'd for a Chevelle, or is this just an oversight on their part?