I also have a Q6600 running at 3.6, and at much lower clocks i get a 17800, with no vmods. I just pulled the stuff off and its running back to where it was.

I need to get a 50k trimmer for the mem, my 20k at 20k put the mem around 2.01. And i didnt even have a trimmer soldered onto the gpu, i had to run clip leads to a big 20 turn 10k, wich got tricky to manage near 1.2+v.