to be honest i dont know the difference between the 1 or 2 but if its 2 doors and 4 doors thats the difference the tail lights should fit but your doors and stuff wont i had trouble finding parts for my nova i had a 4 door at one time and everything was 2 doors im just taking a guess though

 

They are not two different bodies. They are both B Bodies. As far as two different bodies there is differences in 2 dr and 4 drs, sedans, hardtops and convertibles but they are all B Bodies. Although I nave not tied switching the taillights from one to the other, I could see no reason why they would not fit. Usually the differences in various models of a particular body are appearance items, however fitting a part from one model to another should not be a problem. In addition to the Bel I and the Bel II, there was also the Satellite that year. All the same bodies, but different trim, different seats and as someone else noted, possible different side apertures which is the body. You have a two door and a four door. There is also a convertible, which I have and "most" of the parts from the 2dr hardtop also fits the convertible.