The thing I would be worried about from my own personal experience during the Woodward weekend is being basically cooked alive inside a modified car with black interior. I'm not sure if actually shutting off the heater core lines at the engine would help or anything, but even with the vent doors open, and the windows my car becomes just about unbearable in any heavy traffic or even just cruising on the freeway on a 90 degree humid day. I'm 5' 11" and about 180 lbs and I sweat like crazy in that thing on days like that. Short of carrying extra charging system stuff, I can't imagine having too many breakdowns along the way if you keep your eye on stuff and have real gauges.
Yeah, this was one of the main motivators. The car handles a lot better, and just in general feels really good compared to with the 15's. I even had some good 15" tires (BF Goodrich G-Force Sports) and these Continental Extreme Contact DWs are a big upgrade. I liked these tires on my Colorado that's lowered for the last 5 years. Since I work for Conti, I get a few sets at a good discount every year so that helped. Otherwise they make what my friends who autocross refer to as "Jesus Tires", the Bridgestone Potenza RE-71R in 275-35-18. Those things are insane gumballs.
IIRC that size came on enough Corvettes and Vipers among other things that the selection should be around for a while. If you don't want to go that aggressive, they make a lot of the same tires in 245-45-17.
The standard BF Goodrich Radial T/A that everyone buys is a god-awful horrible tire for any real driving. It's hard to think of too many tires that are actually lower performance anymore.