I had a Warpengine 040 running at 28mhz, and as the crystal was socketed, i thought it would be a nice easy overclock. but could i get a 33mhz crystal? nope. managed to get a 40Mhz crystal chip, and remembering how hot my old cyberstormII 040 got, i pulled the little heatsink off and cleaned off the glue and heatsink paste. and the chip turned out to be a 25Mhz version (full FPU, MMU etc.)
bolted on a BIIIG arse heatsink and fan with a spot or two of heatsink grease, popped in the 40Mhz crystal, booted up fine. nothing flaky, or after continuous tests (involving AIBB and Quake) it all looked fine. one thing was puzzeled me. in stuff like show config, it didn't seem to think it had an FPU. this struck me as ok, as the 040 may have disabled the FPU due to the speed and possible core temperatures it was running at. i dunno. but even tho it reported no FPU, the FPU tests and Quake, and other FPU requiring software ran fine, so shrugged my shoulders and carried on. if you are over clocking an 040, bear in mind COOLING COOLING COOLING! and heatsink thermal paste can make all the difference!
(just not too much, just enuff to fill the imperfections in the surface of the chip and base of the heatsink. if you are going to glue the 'sink to the chip, but spots of glue on the outside of the chip/sink so you arn't interfearing with the heat dissipated to the heatsink) :-)
