as klownin79 said, Unlocking your chip will allow you to run at higher fsb if you lower your multiplier. Unlocking doesn't necessarily mean you'll gain 100mhz or more in your o/c. Maybe 10-20mhz at the most if any gain at all.
You should be safe as long as your temps don't get too high. What chipset is your dragon Plus? (KT266a, KT333, KT400?) If you have a KT333 or KT400, you might not have to unlock at all if you've got good cooling. With good cooling, many reach 11X166 without problems.