it will increase your PCI frequency which may cause some devices to react poorly to the overclock, however, the newer 333 boards have a split, in order to choose how much bandwidth goes to each part of the system.
166 on a 133 based board is gonna be rather tricky. Your chipset and CPU are not designed for this speed! I would aim more like 140 - 150 FSB on that board, and thats with good ram to keep up!
AthlonXP 2500 Barton
MSI K7N2 Delta (MS-6570)
Nvidia Geforce FX 5600 128MB VIVO
512MB (2x 256MB) Crucial PC2700
2x 120GB Seagate Barracuda 7200.7 8MB
52x/24x/52x Lite-On CD-ReWriter
550 watt Q-Tech PSU
Superflower silver case
T1 Internet Connection
AOC 17" 7Klr