Have you spoke with the seller/builder, he could be a great asset?
It has always worked well in Colorado. He said it use to get on the trail (but never overheated) so he went to an all aluminium radiator, but it kept getting busted on the trail so he switched it out to the current copper unit. He also had three electric fans hooked up at one time in place of the stock setup. He said that it worked no better and sent it back. He was very anal so pretty much everything mechanical is in perfect condition.