I have an 82 12a auto, soon to be a 5speed, and i was looking into getting a RB header used from an 84 12a 5 speed. I know racing beat lists them seperately and has different part #'s 16010 and 16012 respectively. Anybody know the difference between these and if the differences can be overcome? Any help will be appreciated.

 

Headers will fit all 81-85. only difference is in back pipe and muffler. Just use the header with whatever setup from there back. rx7doctor

 

The only thing that I could find is a reference in a British Victoria that Mazda used 2 different sized catalytic converter. Look at the note at the bottom right hand corner of the page I have attached.

 

He isn't going to have to worry about that. The fitting from point A to point Z is the same lenght when using a rb system. The rear muffler is the only difference as far as the bolt pattern goes. Even using one year or the other as far as the silencers goes it will fit by either pushing the system back or pulling it forward. I have interchanged them all. You can even use a se header on any s4 or s5 N/A. The only difference is when you try and bolt up the silencer from a s4/s5 to a se you would change the flange and vice verus. rx7doctor