I am racing a 1st gen ('81) in the GT Sprints at Mosport, Ontario this season and I have a question seeing that I'm a converted Toyota guy.

I have heard that the 12a is a tougher engine than the 13b with port modifications and hard use.......true or not????

Thanks,

Steve
racerguy19

 

Stick with the 13b. There are more parts avaliable for them, plus mazda is not make anymore 12a rotor housings any longer. Also the 12a is not really tougher then the 13b or vise versa, it really depends on how you drive them and how you maintain them.

I hope this would answer your question..