Q9550 > How to achieve higher FSB with lower VCORE???

Hi all, recently got my new build up and running, full spec is:

700w OCZ
GA-EP45T Extreme
Q9550 E0 (cooled with TRUE120 push/pull)
2x2GB G.Skill RipJaw DDR3
Sapphire 5850 (1050/1200)

Anyway i hit 4.2ghz pretty easily with most things on auto, whilst testing for my max fsb limit im able to hit 4.5ghz without too much effort. The problem is i can only run it sensibly at 4.2ghz, im having to set the vcore in the bios to 1.400v (cpu-z reports it in windows at 1.38v just outside the intel reccomended volts).

I think with everything setup on the other options correctly i could lower my vcore and get the higher fsb i know i can reach. Im not familiar with some of the options in here, if someone with more know how can help me that would be great.

Here are my settings in BIOS now (prime stable at 8 hours > idle 40c max 63c, havnt run it any longer yet):

MIT
RGB > AUTO
CPU Clock Ratio > 8x
Fine CPU Clock Ratio > +0.5
Frequency > 4.2GHZ

**** Clock Chip Control ****
CPU Host Control > Enabled
CPU Host Frequency > 495MHZ
PCI Express > 100MHZ
C.I.A.2 > Disabled

**** Advanced Clock Control ****
CPU Clock Drive 800mv
PCI Express Clock Drive > 900mv
CPU Clock Skew > 0ps
MCH Clock Skew > 0ps

**** DRAM Performance Control ****
Performance Enhance > Turbo
X.M.P > Disabled
MCH Frequency Latch > AUTO
SPD > 2.66D
Memory Frequency > 1320MHZ (8-8-8-24-2T)

**** Mother Board Voltage Control ****
CPU VCORE > 1.40000v
CPU Termination > AUTO
CPU PLL > AUTO
CPU Reference > AUTO
CPU Reference2 > AUTO
MCH Core > 1.400V
MCH Reference > AUTO
ICH I/O > 1.600V
DRAM Voltage > 1.660V
DRAM Termination > AUTO
CH-A DATA VREF > AUTO
CH-B DATA VREF > AUTO
CH-A Address VREF > AUTO
CH-B Address VREF > AUTO

Advanced BIOS Configurations
CIE > Enabled
C2/C2E State Support > Disabled
C4/C4E State Support > Disabled
EIST > Enabled

Im also using Bios F4 (the latest full stable one).

Thanks in advance for any help anyone can give me, im sure i can get the same/better overclock with less vcore, i just need to know what to change to do this.

Cheers!