After 8 years and 85k miles added, I'm getting ready for a clutch replacement on my 08 Mazda6 i . Car is going on 160k and the clutch definitely feels like it'll be done in the near future (still drives great though). Will probably just get a new exedy kit, but something I've thought about a lot is how much a 6th gear would be great (there are 85mph zones near me and sitting at or above 4k rpms isn't a great feeling).
Wondering what compatibility there is between 6speed boxes from either a Mazdaspeed 3, or 2nd gen 3's and 6's . I'd love to have a trans ready to go in advance of the clutch job. Also, since my intermediate shaft is ready to be replaced, it just makes sense to make the conversion at the same time. Wondering if anyone has either done this before, or knows about the 6 speed boxes from later MZR cars.