Intel Core 2 Duo E6750 OC Help

Okay guys ive never really messed and overclocked with these core 2 duo chips lol i was always messing with the Athlon 64 x 2 chips when these bad pups came out. lol anyways i got this rig found it in the trash bought 4 gigs of ram and started it up and bam it works? im like WTF mate? okay so it has the following specs.

Case: Apevia ??? 2 x front 80mm fans
1 x top 80mm fans
2 x 120mm rear in Water Cooling Closed Loop from Cyber Power Push/Pull

Ram: 4 x 1GB DDR2 667 @ 800 Stock Timmings & Voltage

450watt PSU Raidmax

Motherboard: Asus P5NE - SLI

GTX 8600 GSO x 1

1 x 320GB Western Digital Cav. Blue @ Sata II

Windows 7 Ultimate 64bit

CPU: Core 2 Duo E6750 Currently stable with 24 hour test of Prime 95 @ 3.15Ghz @ 1.5 Volts (JUST FOR KICKS!)
Idle Temps: 39/42 Max Load Temps under Prime 95: 55/59
Max temp for CPU: 70c I think?
Max Voltage: 1.5Volts.
Screen shots of cpu - z below

CPU-z Shows current vcore @ 1.472 have it set to 1.5 volts in bios
trying to overclock this thing to the max
and as we can all see for temps THIS THING HAS QUITE ALOT OF ROOM STILL! , but i need some help as i have no expierence overclock with the c2d's! please help lol



if i try and raise the voltage pass 1.5 the max ive tried is 1.518volts and it wont boot but it also was tried @ 3.4Ghz also. since i have a lot of room for temps what is the safe vcore i could set it at? maybe a couple hairs above 1.518? im asking cause it wont boot with anything above 1.5 and below 1.518? so idk i didnt want to go any higher till i got some help and opinions!

so i can get it stable at 3.2Ghz with prime95 for12+ hours it was @ 3.24 ghz @ 1.5volts and let it run all last night in prime 95! so thats good i guess?
what can i do to further my OC! ??? thanks
Daniel!

UPDATE!!!
Managed to get the following OC Stable!:
3.219Ghz @ 1.552 Volts
max Temp under Prime 95: 67/70C Core 1 & Core 2
DDR2 677 Ram @ 800 @ 1.8Volts @ 5-5-5-15 (2T)
Idle Temp is 47/51 under core temp
Max load is 67/70 under core temp in Prime95 After 6 Hours

if i try 3.3 ghz or 1650 PSB it wont POST
but im afraid to GO ANY HIGHER DUE TO MAX Vcore of 1.5volts IM ALREADY over at 1.552!
im on water cooling so? idk what are my limits?

I have that chip on an Asus board and it will clock all day at 3.6. From the looks tho your RAM might be an issue if you can back the memory ratio down some I'll bet you can get more out of her. If you have DDR2 800 rams you could get a 450 FSB fairly easily. I think too MAX daily use for a core 2 is like 1.65v so @ 1.5ish you are plenty safe. You also may have to adjust the Load-line Calibration(assuming your board has this). Watch your vdrop/droop.

Z