[skip this if you like] Ok, i have one of the worst mobos i could. anyway, I want to get the Thermalright Ultima 90 because here the ambient temps. are quite high - above 90F and at times by Q6600 reaches temps. above 90 C (i reseated the heatsink several times, so the thermal compound cannot set.) Instead of getting a new thermal compound, I think it would be better to get a new HSF as this would also be useful for future Ocing on different mobos.
bottom line- I want to install a Thermalright Ultima 90 on my Intel DG31PR. Can I install the backplate comfortably or will some soldering in the back obstruct the backplate?
If you removed the OEM HSF, you need to clean the old paste and replace it with Artic Silver 5 or equivalent thermal paste. Otherwise your CPU will overheat.
Few people install such a HSF on a motherboard like yours. Contacting Thermalright still is your best option. Is there anything sort of abnormal under the CPU area with that specific motherboard? I've bought a few Intel motherboards (and I still have one) and they were nicely built.