Jerry,
Mine was built Nov, 05 and delivered in Jan 06 to a dealer in Florida. On flat ground I run 188-190 and the trans around 175, the motor will hardly ever get over 196 that is where all kicks in and it cools right off. I have got it up to 200 once pulling Raton Pass when it was hot around 90 outside, but that was at a dead pull 4th gear 100% load, I shifted down to 3rd and it cooled right off. Coming out of Denver last year on I-70 all the way up through Eisenhower tunnel at 11K and she never got over 198, of course the outside was around 70 or so.
I have one big cooling fan and that baby really sucks a bunch of air when on high speed. I need to get in there and check the motor mount as I have heard they have a history of cracking.