When we were talking about radiators last week, general opinion seemed to be that the main advantage of aluminum was lower weight.
I don't see how this matters that much. (Note: I'm not trying to argue - just saying I don't understand.)
Here's my thinking: Most of the time, jeeping is a low speed, low RPM activity. You're not usually trying to fly up the hill or through the mud at max speed and power. It's rare to have the gas pedal floored when off-roading. So there's almost always plenty of "oomph" left in the vehicle which you could get by simply pressing down further on the accelerator. Further, most of the time you get stuck, it's because the wheels are spinning and not getting traction, or perhaps because you are hung up on something, not because the engine doesn't have enough horsepower to turn the wheels.
Also, in the overall 3,000 or 4,000 pound weight of a jeep (maybe pushing 5000 lbs with passengers, winch, ice chest, etc.), the small relative weight difference of aluminum radiators seems like an awfully small drop in the bucket. Not to mention that additional weight can actually help a vehicle gain traciton.
So, all in all, it seems to me like you're getting an extremely tiny horsepower improvement which probably isn't even needed. And to do so, the tradeoff is that you're now running aluminum, which several people have said is more expensive, harder to work with, and more easily damaged than a traditional radiator.
This just seems like a lousy trade to me. If you're that concerned about weight, there are other things you could do, too, such as running without that big ol' heavy spare tire, but that makes about as much sense as far as I can see.
Am I overlooking something???