qx6700 OC questions temps please help

hello all, here are system specs
qx6700 @3.2ghz *-(12x266)
4gb Corsair xms2 pc8500 1066mhz 1:1 ratio 2.2v
2x bfg 8800gtx oc sli watercooled with TT tmg nd4 158.45
mobo Asus Striker Extreme bios rev 1303
vcore 1.35
1.2v ht 1.35v
nbcore 1.35v
sbcore 1.55
rest to auto
OS Vista 64 ultimate
case kandalf LCS 6x 120mm fans 1200rpms inside case + 2 x90mm
kandlaf lcs 360mm x 120mm radiator 3/8 tubing, 550lh pump, to the 8800gtx sli as5 grease
swiftech aqua 120, 240x120mm radiator 1/2 tubing, 1200lh pump, cools only the qx6700@3.2 as5 grease

both radiators are not in the case to avoid hot air inside the case.

now here is my question, i just finsh the installation of the swiftech system, and im confused about the temp reading, is it posible to have tht much diference between cpu, and core temperatures? or it means i apply the as5 grease worng?. i put lots of work to sit the waterblock perfectly

CPU:16c after 2 hrs idle (43c load, 2 instances of orthos ,10 priority for 30 mins) back to 17c after test
CORE: 1,2,3,4: 44,44,40,41c after 2 hrs idle (67,66,66,65) afte 2 instances of orthos ,10 priority for 30 mins)
room temp 20c ( i maybe wrong most likely, but anyway, i thoght it was not posible to go below ambient temperature? i got it wrong?).
so how it looks? i really want to do more oc and reach 3.5ghz, shall i doit?? with the x13 multipier? or push the fsb?
eitherway you guys think i will need to increase the voltage? Vcore.
sidenote: if i measure the temps with fanspeed 4.32 the readings are 15c lower in the 4 cores so wich i should trust? yay heh, you all have always help me when needed TY guys!!!