Bubble
Your DDR may be your problem when doing this, but possibly you could keep your DDR at 266 in the BIOS. The only problem with doing that would be that your CPU/DDR would be out of sync and you wouldnt see the full benefit of increasing the FSB.
Your 2000+ may run at 13x 166 but that will depend on the core(Pally, T/Bred A or B) I would suggest that you drop the multi to 10.5x then get the FSB to 166 and see how it goes, if its OK then you can try setting the multis up one step at a time.
As I said your PC2100 is your main obstacle so if you can try and get some PC2700 or faster, then you will see the benefits as you will be running sync.
AzureBOB7
Expect to get around 1800MHz from the pally, you may get more but that will depend on the stepping and the max really you could hope for is around 2 Gig.
Hood