I overclocked my 400mhz g3 to 450mhz L2 cache @ 225mhz 1 gig ram 20 gig ata hd. I used the stock speed control plug and removed and rearranged the existing clips with a pair of needlenose pliers and a pin to pry out the clips. For cooling i went to tigerdirect.com, and bought the dual fan pci slot exhaust fan. Then I removed the front speaker and the foam infront of it. The fan hole is level with the heatsink for the processor so it give a nice flow of air though the fins. You want to avoid too many directions of air current using more fans can actually make things worse than one fan. My current cpu temp is not noticebly higher than stock 42*C. My ambient temp in my room is never higher than 75*F, and my case is on the floor. I have never had a crash in 15 months and improved my benchmarks from 12.94 to 27.81 (specs from xbench utility). I dont think a directmount heatsink fan is the way to go it disrupts the flow of air in a g3 case. Also, make sure you clean the case and don't let dust build up.