06 frames run 23x8 reducers upper and lower, they went to 10mm for 07 onwards
i would recommend getting either old fox steel 3pc pin and collar hardware or rockshox hardware as they have decent sealing to keep crap out of the eyelets, last set of 2pc reducers i put through my sunday lasted half a winters riding, went to sealed 3pc and havent changed them since (going on 2 years)
It wasnt the hardware that the shop measured though. It was the gap where the rear shock goes in the lower link and the gap where the shock goes in the upper small pivot triangle.
Do you mind if i take a picture of it and send you it? U seem to know more about this than i do