If the frame is sound (not crashed) it will hold you. If it is the aluminum lugged 2300 (pre 1999 had carbon tubes bonded to AL lugs), check the joints to be sure they are good.
There are some +300 pounders here on CF bikes. Get some compact or touring gearing and you should be fine. Remember to spin and not mash the pedals, your knees will appreciate it.
http://www.vintage-trek.com has some info on this bike.