If you can transfer the existing surface mount pull-down 10K-ohm resistor, (shown in the image linked to above as 'remove this resistor'), to the pads indicated for the pull-up resistor, that's the neatest solution. But the resistor is very tiny, and resoldering it is a bit of a challenge! If you can't get that to work, (or you lose it, which is easy to do!), then just get the smallest (lowest wattage) 10K-ohm resistor you can find and use that. The Radio Shack link you show is for a 1/4 watt resistor - that would be fine if you can't get the smaller 1/8 watt one.
If you haven't already done so I'd suggest you read my posts on pages 53 and 54 of this tread - http://www.wimsbios.com/phpBB2/topic4046-780.html
- since I found the 100MHz FSB mod to my 390E to be only partially successful! Actually it wasn't the FSB mod that was the problem, but rather the fact that I haven't been able to get a P-III CPU to run properly
- the problems I encountered are in that thread. I was able to get the original P-II/300MHz CPU to run at 450MHZ after the mod, but none of the higher-speed P-IIs (333, 366 or 400) would run overclocked by 50%. So, unless you can get a P-III to run properly, you could achieve the same (or marginally better) upgrade effect by staying with the 66MHz FSB and using a Celeron 466 CPU! I don't know what it is about the 390E and the P-III CPU, but they just don't seem to work together as you'd think they should - after getting the FSB to 100 of course. If you decide to try the mod I'll be really interested to hear if you are able to get a P-III running satisfactorily.
For now I've pretty much given up on trying to get my 390E past the 450MHz that I have now with the original P-II/300. Instead I went to eBay and picked up a 390X for a good price, and now I have it running just fine at 850MHz with a 850/700 speedstep CPU modified per sharedoc's instructions! In the BIOS and in DOS the CPU shows as 700MHz, but strangely once booted into Windows 98SE it's running at the higher 850 speed without any need to run the DeepSleep utility! And that doesn't seem to be a fluke since it's been at 850 every time after booting to Windows. In DOS I can get it to the higher speed by running DeepSleep.
If you do try the modification, and especially if you then try a P-III CPU, please post your findings!