They’ve always been rated up to a 150mm fork, the bigger issue with older Fives is the Manitou shock which was a bit rubbish so look for one with an RP23 preferably.
Other thing is they have a longish headtube so you may have to work at getting the bars back down to a reasonable height (flat wide bars or upside down stem) depending on how you like your setup.
I rebuilt my ’05 frame this year with 150mm dual air Revs, new RP23 and offset bushings – had an awesome week on it last month in the Sierra Nevada, perfect bike for those trails 🙂
http://s18.postimg.org/ky5t1pr09/P5060031.jpg%5B/IMG%5D