Help with Jumpers on a XPS-R 400mhz Dell

[OverClock400XPSR]

Is it even possable to over clock thins thing? I have all stock components except for my 2 AGP cards linked. My chipset is an Intel 440BX AGPset. In the jumpers section it says that there are 2 settings, 350 MHz recovery mode and 400MHz normal mode. My system clock is at 100MHz.
BUS Speeds :
AGP: 66 MHZ
PCI: 33 MHz
ISA: 8.33 Mhz
If anyone has overclocked this thing please tell me your jumper settings and anything else I need. Gundamrealm@crosswinds.net

[OverClock400XPSR]

Oh yeah, im going for 448 or anything you have, It is MMX enabled too