Guess what?  A Quantum Bigfoot IDE drive will not fit into the 5.25" drive slots of a Dell 500SC chassis.  At least, not and have the front panel cover on.  Screwing in the drive means that about 1/4" protrudes from the front, making it about even with the faceplate of the cd-rom.  *sigh*
I just have it set inside for now.
Also, the Bigfoot drive causes a 'drive operating outside normal parameters' error on boot with the Dell.  I think the Dell SmartDrive circuitry cannot detect the bigfoot - after all, we are talking fairly old tech with that drive.  Several years old.  I think the Dell simply cannot deal with the Bigfoot and thinks it is failing, when it is actually perfectly fine.  ignoring the error every boot is a pain, but it formatted fine - no bad sectors at all.