I dropped in my XP1600+ set to 1.95Vcore, 10.5X Multi, 145FSB, 2.7Vmem, for 1523mhz.
Room temp is 22C, water temp is 25C, and load temp is 28C!!! My hose is 5/16" ID, and my connectors are 1/4"ID, pump is 185GPH in-line and my rad is pictured below. So far so good.
Note the mobo is on my test bench, upside down from a normal case install.