I have located a worn out 13b from a 1985 RX7 for sale cheap, and I need a replacement for my 1975 13b. Are all the parts still available for rebuilding the '85 model (It's Sunday, so I can't call the Mazda dealer)? I ask because I have read that Mazda is not selling some parts for the 12A's anymore (like rotor housings, which you can't fabricate in your garage) and I understand that many 13b RESI parts are not interchangable with the "86 and later engines. On that subject, can I use the lighter rotors from the '89-'91 engines in the '85?

 

Yes, the all 13b rotors can be interchanged with other 13b's.