Between 1979 and 1981 what parts are interchangeable on Nissan Datsun 280ZX?

According to Zcar dot com and Hybridz dot org since i was in need of an answer, i have found that near all parts are identical. Nearly 90%. Most body pieces will interchange, but i am unaware of minor differences (if any) in the body. I myself am going up to look at a 79' 280zx to be a parts car for my 82' 280zx. What i do know positively is 2+2 and coupe's body parts are not interchangeable from the firewall back. But everything else such as interior should be. The hatch from a 2+2 and coupe may interchange as well, but i am not sure of that. So in conclusion if you are considering buying a parts car for your year car X, and the parts car being a previous year car, it should be mostly interchangeable. The reverse way, i am unsure of though.

-Heath