I hit 102c on my Core i5 HP DV6. That laptop had terrible heat dissipation. It would hit 75c watching youtube videos at 720p. I even got turbo problems and the laptop stayed at 100% load because the clocks got stuck at 800Mhz. Needless to say it sucked.
It'll still be waaaaay cooler with the Noctua. :P
Assuming you didn't overclock, your stock cooler should do fine. My 3450 idles at 30C, with web browing and youtube it goes up to 35, in games or renderring, it never goes above 55C.
Correctly apply your thermal paste and make sure your cooler *Snaps* into place..