Before measuring a radiator, or replacing a radiator it is important to determine which design you have. Radiators are constructed in one of two ways. The first is called downflow, while the second is considered a crossflow.
With a crossflow radiator, the overflow tanks are on the left and the right of the core and the coolant travels horizontally.
Conversely, with a downflow radiator, the overflow tanks are on the top and the bottom of the core and the coolant travels vertically.
Whether or not you have a downflow or crossflow radiator depends solely on the design of your vehicles' engine. Not one design is better than the other.