Replace the old thermostat housing on your 1999.5-2003 Ford 7.3L Powerstroke with the XDP 7.3L Billet Thermostat Housing XD277. Unlike your factory thermostat housing, the XD277 is built to last, featuring a billet aluminum construction for durability and a black anodized finish for superior corrosion resistance. The added rigidity of the billet construction also eliminates the common leak points from the 3-bolt flange on the factory housing. XDP's Billet Thermostat Housing is more than just a dress-up part, it's the perfect addition to any 7.3L Powerstroke.