TWR0001 is a downflow radiator for Western Star trucks, model years 2002 to 2013.
The core measures 33.875" high by 39.5" wide, 2.25" deep. It has a 2.5" inlet at the top right and a 3" outlet at the bottom left or right. There is no integral oil cooler and no filler neck.
It replaces 30 OEM and aftermarket numbers, among them WES86, 800086BT, 0521113000. Searching any one of them will find this part.
On radiators the inlet and outlet positions, and whether the unit carries an oil cooler, decide interchangeability more often than core size does. Two radiators with identical cores are frequently not interchangeable.
