Thanks Jerry ... I'm pretty new at all things auto mechanical and am learning as I go. Good to know what the running water temp range is.
I left out one factor in my original post ... when removing the old radiator I broke off a 4x6 inch piece of the fan shroud near the top. Man that thing is brittle! Until I can find a local guy with a shroud he's willing to sell off a parts truck (those things are $110 new), I'll patch it up with duct tape to get good air flow through the radiator.
I'll be taking the truck to Salem, OR from Eugene, which is about 60 miles each way ... it will be the first chance I've gotten to really get it on the highway and see how it does.