TWR0003 is a crossflow radiator for the Western Star 4900, 4964, Low Max, model years 1998 to 2007.
The core measures 38" high by 34.375" wide, 2.25" deep. It has a 2.5" inlet at the top left and a 2.5" outlet at the right. There is no integral oil cooler and no filler neck.
It replaces 210 OEM and aftermarket numbers, among them WES13, 1806334, 1A15458G. 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.
