FIttings and Hose size
Gas and diesel pick ups usually have a pretty big trans cooler. In a cold climate (like PA) that can be a problem. The trans won't warm up enough when the fluid is too cold, and it stays out of OD. Not good for fuel mileage, among other things. The answer for them is a winter cover.
For you, I would go ahead an install the cooler you have. You already own it. Route the fluid from the trans to the new cooler, and then into the stock heat exchanger. During the winter, the fluid will be warmed a little bit and maintain a stable temp.

