I own an eMachine 333cs, and decided to boost its performance by swapping out the original Cyrix CPU with an AMD K6-2 CPU. As I gathered information, I got in touch with several other people with similar experiences, and we banded together to pool our knowledge into a FAQ and a bunch of Yahoo! groups.
From this page, you can get to:
The eMachine overclocking FAQ, mostly specialized to the eMachine 333cs and other eMachines with Delhi-III motherboards.
The eMachine overclockers Yahoo! group, which I moderate.
The eMachine upgraders Yahoo! group.