p4 2.8C @ 3.6ghz can i go any higher?

hi,
I've just gotten a P4 2.8C and clocked it at 3.6ghz at 1.55v
temps are 25C idle and 35C load

im using an asus p4p800-se motherboard, 1 gig pc3200 ram with heatspreaders (2.5-3-3-7) 5:4, hercules prophet 9800 pro 128mb

i've tried 3.7ghz and it locks up at 1.6v

forgot to add it has m0 stepping, and 30 cap.

My 2.8C M0 does 3.64Ggz 260FSB using 1.650Vcore in BIOS. (btw all M0's are 30 cappers) It's 24/7 general use stable and runs SETI all the time, but I need to back down to 250FSB to be dual Prime95 stable. I'm steadily getting part by part for a good watercooling setup hoping to get higher and Prime stable. Getting higher can be in tiny things, try to raise AGP and Dimm Voltages cuz some board/Ram combinations hate running at 5:4