48'c to 49'c??? that seems a bit high for 3.5ghz Q6600 G0 stepping... but ur installation seems very clean... maybe u still got air bubble trap in ur loop...

try get the air bubble out frm the radiator as radiator mounted at the top tends to trap air bubbles inside easily, try remount ur waterblock, i also experience high temp cause of poor water block mounting. Try use core temp to check the temp instead of bios temp sensor.

remysix: you just assembled the set and bled it that way with the casing upright and you didn't tilt it at all? if that is so, i can pretty much bet that there is still air inside the radiator.
since the inlet to your rad is on the side facing u, and the outlet on the other side, you have to tilt the entire casing towards you to get the air out. but you would also have to be aware of air going back into the loop from the reservoir.
thus, for those having their rads on top, i recommend plumbing the inlet side of the rad to be on the side away from you, and the outlet of the rad would be the one nearer to you. thus this way you can dismount the reservoir and tilt the casing full flat to the ground away from you to allow the air out of the rad. if you have someone to help you, you can then ask him to hold the res upright while you tilt the case around according to the flow of the res to get the air out.
reason behind this is because these radiators are two pass rads. the water enters from one of the inlets, flow down to the end of the rad on one half of the radiator, then at the chamber at the end, the water makes a turn round to the other half of the rad and flows back to the outlet. so when you bleed your radiator, bear this in mind to tilt the radiator according to the flow direction. air will always be above water, so use basic science lah to flow the air out.

dun expect so much from WC to Q6600....
stock HSF easily get 90C under load...
i've similar setup like you....
Idle = 35-40C
load = 60-65C
tats the best i can do before Metalzone bro send me Fuzion...
let the TIM settle you'll get slightly better result...
3.85g@1.39v daily use.
just reference maybe some help...

i think nirox is more noisy then eheim, get laing d5 if got budget... more silent, flowrate, and h.pressure...

but you posted in my thread u wanted smtg submersible right?
the Laing D5 and DDC CANNOT be submerged.
so that leaves you with the Eheim's, Nirox's, and the most silent one would be the little D-TEK DB-1. I'm trying to get hold of some of those DB-1's.

the D5 is already quite silent. silent enough for me. it will make noise if the vibration isn't dampened. the DDC and DB-1 makes less vibration.

according to cooling master's test, lapped+bowed is better than lapped+unbowed. so don't worry about that. but course, lapping the CPU=warranty void.

It will as Artic Ceramic is not really a good performer under load condition ...

yeah...btw dun try to submerge ur mcp655 oh.... mcp 655 is not submergable