You can actually run 8.6 on a Nubus PowerMac. It'll be slower than 7.5.5, but seems to be about the same, speed-wise as 8.1, maybe a little quicker, since there's no 68k code in it. I've not tried running 9.2.2 on one, but I do have a hacked version that I originally installed on a 7500/100 that I plan to try with the Piltdown Man board once I get a 6100 chassis. Was going to use the 660av chassis that I have, but didn't want to hack up the back panel.

-J