I have an 04 Mazdaspeed with a 4.1 Torsen II.

I want to change the ring and pinion to a 3.63 .

I went on the search sites, like car-part.com and others for a Mazda 626 Diff from (80-82). No dice.. or about the same as new gears.. (550)

I saw this chart.. what other cars can I get the ring and pinion out of that are compatible?
Solomiata : Transmission : Ring and pinion tooth counts

Getting close to 3.63 (like 3.7, 3.727) would be fine too

Thanks
Jeff

 

Here ya go. Comes with the speedo gear, which you will need.

Ring & Pinion | Mazda 1.8 Performance Parts

KMag

 

you can order the parts direct from mazda, they were on the austrailian 01+ cars.