Still, that's DAMN hot!
I can't believe it's not crashing
NVidia do tend to blather the GPU's with paste so a clean and some new paste should help a bit. Are both cores reporting similar temps?
Also, when you say you vacuumed it out, did you have a look past the fan to see if it got it all out. With mine I can vac all day but I can't get the bit's blocking the fins out. I had to strip the cooler off (which is a fiddly job) and clean it properly and I saw a good 15*C temp drop. Just be careful not to damage or lose the thermal pads from the memory chips. AS5 worked fine for me on the GPU.