Heater Assembly Interchangability

I decided to gut the interior in my zed, so I could POR 15 everything. Anyway when I took the heater assembly out. I found it was being occupied by mice at one point. Anyway everything was stuffed with grass. and I guess the moisture rotted most of the metal away. I was wondering which years of zed heater assemblies are interchangable.

I SHOULD HAVE PROBABLY MENTIONED THAT I HAVE A 1970 240Z WITH NO AIR. I HAVE BEEN SNOOPING AROUND, AND FROM WHAT I HAVE GATHERED THE HEATING IS THE SAME UNTIL 73, CAN ANYBODY CONFIRM THIS. IS THE LATER VACUUM CONTROLLED TYPE SUPERIOR IN DESIGN, IF SO, IS IT COMPATIBLE WITH THE EARLIER SETUP.

THANKS