What size radiator comes with the tow package?

This is a question. We have a truck like yours, and have had problems pulling up mountains with a lighter camper (4K lbs) Do you know what your axle ratio is? Impressive that you have been able to pull 24 ft camper. We also have installed trans cooler, did not help. Thinking of changing rear axle to see if that would help. Any advise would be appreciated before we spend more money. Sweet riding truck that is paid for makes it hard to spend $$$ for a new one. Thanks for any advice.

Thanks for the reply. I have the crew cab (4 door) with the trailer package which I believe includes the 3.73 rear axle. Some radiator on line sites say a 1.25 inch thick radiator is available for this vehicle which I think was also included with the trailer package but AC delco site only lists one radiator for this vehicle which is about. 1 inch thick. If a 25 percent thicker radiator provides close to 25 percent better heat dissipation that's a big improvement. Maybe ill try talking to a local radiator shop and see what they say. By th way I climbed a 5000 ft mountain again with the trailer, when the temp gauge got to 3/4 mark (before the COOLANT HOT warning would announce) I would stop and keep the engine idling, open the hood and it would cool back to normal in 3-5 min. I would start up again and pull over again when it got up to 3/4 on the temp gauge. Had to stop 7 times to get to the top but doesn't appear to have hurt the truck at all, just added an hour to the trip.