Hey i have an Evga P55 Sli and a Thermalright true. The problem i had is is you look at the backside of the P55 motherboards you see the metal back plate of the retention bracket. When i try to use the 775 holes that back plate prevents the true back plate from going in the holes all the way. if you hold it steady you may be able to get the screws in but i was worried about proper contact. If you are using a 775 hsf with pushpins then your ok. I am using the stock intel hsf until i can find a place that has the 1156 bolt thru kit for my true