CPU cooler replacement and shroud mod on X51 R2 : r/Alienware
X51-R2 CPU Cooler replacement - Dell Community
X51 Heat Sync Casing replacement - Dell Community
X51 R?, need to replace heatsink - Dell Community
Old & New (Bring Alienware X51 R2 back to life) by meng8123 - Intel Core i7-4770, GeForce GTX 970, EVGA Hadron Mini ITX Tower w/500 W Power Supply - PCPartPicker