Well, I cranked my RAM down to the lowest latency supported by the motherboard and ran 2 succesful passes of memtest86. Then I decided to press my luck and try to overclock the thing again. 266Mhz (75x3.5) POSTed but wouldn't boot linux. 250Mhz (88x3.0) toasted my BIOS settings. So, now I'm back to 233Mhz, and I had to do a lot of annoying stuff to get my ISA network card to work again.
(addendum) whoops, posted this 3 years in the past. date got reset along with everything else :)