I just replaced mine with one from Rockauto. It doesn't come with a new cap and you'll need to harvest the speed clips from the one you take out but other than that, most everything else fit ok.
Thanks, but I was asking about the all-aluminum custom radiators being sold on ebay and elsewhere. They look like the Mishimoto radiators.
EDIT: I found this video on youtube of someone who bought one of these radiators for his Jeep with a 4.7L. The mounting holes didn't line up, which he was able to fix, but the radiator was ultimately too big to fit in the engine bay of the Jeep. Granted, our Rams have room in the engine bay, but it's a good word of caution.
99-04 Jeep Grand Cherokee 4.7 All Aluminum Radiator Review & Install