TMR0026 is a downflow radiator for the Mack CL, RW, MX.
The core measures 38.625" high by 33.5" wide, 2.25" deep. It has a 2.5" inlet at the right and a 3" outlet at the right. The unit carries an oil cooler at the bottom and a center filler neck.
It replaces 2 OEM and aftermarket numbers, among them 730067, 730067BT. 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.
