TWC0003 is a charge air cooler for the Western Star 4900, model years 2003 to 2011.
The core measures 38.125" high by 29" wide, 2.25" deep. It has a 4" inlet and a 4" outlet.
It replaces 203 OEM and aftermarket numbers, among them CAC142B, 0521206000, 1E005491. Searching any one of them will find this part.
On charge air coolers the inlet and outlet positions and the boot diameters matter as much as the core. A cooler that fits the opening but presents its connections on the wrong side will not plumb up.