A Body Seat Tracks?

Yes. The 75/76 tracks are different due to the Cat. converter hump in the floor pan. The inner drivers side track is much shorter because of this, All the other tracks are the same from what I understand.

Just not sure why the 73/74 would be different than the 70-72. I tried calling the vendor but the lady that answered the phone didn't know. All she could say was that it did not show as compatible in their book for a 73.