My recently modified Quadra 700 with a socket for clock oscillators has now
completed nearly 40 hours of error free operation at 32 mhz (with a 64 mhz
clock oscillator). I have also tried a 55 mhz CMOS clock and that works as well.
On the more stupid side, I've discovered you can use a 40 mhz clock and make
your Q700 as slow as a Centris 610. However, a 25 mhz clock which would have
yielded a 12.5 mhz Quadra 700 (Who'd want one?) didn't work at all.