Series II Manual Transmission Sources
 

I am in the planning phase of a Series II transmission swap. Research and forum searching has informed me that early series II may have a 3/4 shift fork issue. Is there a model year for the series II that Mazda "Got it Right" with the few issues reported? Or just grip and rip any 2009 and up series II?

FWIW: I will be hitting every autocross event in my surrounding regions I can. (C/S Class)

You probably already know this but just to be safe.
 

You won't technically be legal in CS with an S2 tranny swap. That said, the S2 gearbox is geared taller and your fellow CS competitors probably won't have a problem with you getting out of corners more slowly.

What's your budget for the gearbox? Pretty sure you can get new ones from Mazda Motorsports Development at wholesale price. IIRC, it worked out to around $2100 for mine, including freight, S2 shifter and spacer plate.

If you haven't found this thread yet, here are the part numbers:
https://www.rx8club.com/series-i-tec...7/#post4353093

The Mazda Motorsports price is $1750 for the transmission, $150 for the shifter, and $6 for the spacer.

I think there was a small issue with the very early Series 2 manual tranny. Basically the newer it is, the better.