frankly, i would just download a monitor like CoreTemp and see what happens. Keep a close eye on it for about 2 weeks, and see its min, max, and avg temps. Make a record, and check on intel's site for that chips max temps.
The Core 2 duo stock heatsink is exactly the same as the core 2 quad stock except without the copper area at the bottom, it will be be able fit just fine but there may be slightly higher temperature(due to the lack of copper pad). If you are planning on reusing the heatsink, remember to reapply the thermal paste.
well maybe you should wait for CORRECT info, rather than taking peoples word for it. There are at least 3 different heatsinks for the core 2 duo that i have seen. Most of the newer types have a slim style heatsink which is crap, while older ones like my core 2 duo e6600 have the copper core larger style which is good. I have also seen the larger style without the copper core. My dad has a q9300 or something and it has the slim one and when all 4 cores are active in prime95 it overheats (80C+). you really want the larger one with copper core if you are not overclocking with a q9550, and if you OC, get a coolermaster hyper tx3 or 212+.
thanks crowe, im an intel junkie, so i thought i would at the lease get him to monitor his temps. I didnt realize intel had so many different stock HSF's for their core 2 duo series! Crazy. coolermaster makes great HSF's, does the new EVO not support that chipset? i haven't checked on it, but since you already are familiar with it, i figured i would ask. Supposed to be an upgraded version of the 212+ no?