How much vcore would i need to hit 3.2ghz with my p4 2.4 northwood

[imported_xeno]

i am running a P4 2.4 northwood 533fsb @ 2.8 ( it can go 3.0ghz stable highest) on 1.6 volts
Pc3200 Samsung 1 gig dual channel @ 1:1 200mghz 2.5-3-3-8
Asus P4P 800-SE
OCz modstream 450 watt psu

i am wondering how much would i need to raise and would it be safe?