It's totaly possible... In the early days of Athlons They were unlocked meaning if you had the right board you could change the multiplier and overclock very easy... My 700mhz is unlocked...
The was a site that sold "oveclocked" Athlons... As far as I know they simply bought and tested them to see how high they would go... A lot of the 1gigs were simply 600s or 650s...
Now you can unlock them with a pencil or special conductive strips... I bouhg tmy father an AOpen board which totaly ignores the lock on the cpu!!! His 1.2G Athlon ran reliably at 1456mhz...
He turned it downed to 1.3gs for som reason and that's where it stays...
My 1.4g chip should come tommorow, and with my GlobalWin heat sink and 80mm fan and adapter, I hope to hit 1.56 right away and work up to 1.61mhz... The seeming 115mhzFSB limit of my Giga-byte kt133 motherboard...
Oh to answer your question yes it's possible...
Dern, I babble sometimes... hmmm... I'm still doing it... Maybe I should stop...