Are Demon and Dart seats different?

Actually, I have a 70 Dart and 71 Demon/Duster covers. They fit everything well, except the lower rear. But the information you gave me answers the question. Thanks.

So, for those who have put Duster seats in a Dart, how poorly did they fit? I'm leaning toward getting a couple of yards of fabric and making the cover I have fit. That way I know it's the right seat. I just need to come up with a chunk of fabric that is the right color. The people I got the covers from are no help.

I just wanted to throw some cheap covers on these seats. I made an assumption, and now I'm learning from my mistake. Now I know, and knowing's half the battle.

Go Joe!