The thing is about mountain climbing and descent discussions, they usually go like it's one long 6% grade from the US east coast, to the Pacific ocean and then one long continuous 6% grade all the way back. You know, like deep snow and uphill both ways, with walking to school.
Thing is, these challenges, if you will, are far and few in between, during ownership.
With engines, I've never had one that wouldn't climb sufficiently and none should overheat, unless severely overloaded, or something is wrong.
On the National Chevy's, one might notice the curtains on both sides of the engine and the large hole above the radiator to force air over the exhaust manifolds without much excaping. Just an example of how the house manufacture has a lot to do with how the chassis and engine performs.