Radiator cap won't hurt. I sincerely HOPE you watched that gauge close, and shut it down soon after, otherwise you might wind up with a blown HG shortly there-after (not fun to do on any of these 4th-gens).
The cap also might as well be replaced, as I had a similar issue in my LT-1 (cracked T-connector in the coolant system, and the radiator cap didn't like going from 160 to 250 in less than 20 seconds).
If it does it, shut the engine down, pop the hood (get more cold air flowing in), etc. I would not, personally, recommend driving a vehicle, or at most driving straight to a shop, with such a condition. Is it fluctuating (shoots up then back down quickly) or is it more of a slow crawl? Almost sounds to me like air bubbles in the system (takes your incompressible coolant and turns it into a compressible, let's just say the result isn't pretty). Pressure flush, make sure there's no leaks anywhere to allow coolant out and air in.
Wednesday, October 20th, 2010 AT 11:24 PM