How can I tell what year 12a I have? I bought a 79 rx that doesn't have the original motor so I'm trying to find out what gasket set I need...

 

Hope this thread helps...Its basically the difference in the engines. But does your engine have a thermal reactor? That would be the easiest to tell that I can think of? It would be a 79-80. Or look at the exhaust system 79-80 had a heat exchanger newer ones had cats.

https://www.rx7club.com/showthread.p...ght=year+motor

 

Heater core hose - If it has 2 fittings it is 83-85, 1 fitting 79-83.
Beehive - 83-85
No oil pressure sensor in rear housing - 79-80
No EGR - 79-80

 

AFAIK there is now only TWO RX7 12A spec'd engine gasket kits -
-for the 81-82 FB with FMOC. I use this kit for the 79-80 RX7 12A.
-for the 83-85 FB with beehive cooler
see them here:
http://www.mazdatrix.com/b2.htm

Stu Aull
80GS
Alaska