Just watch out with that Vette community when they say "stock". Turns out "stock" to them means no engine modifications. They only mean showroom stock if they say "bone stock". I found that out recently after getting into a big argument with someone about some outrageous numbers he was throwing at us. Turns out his "stock" meant drag radials and some bolt-ons. I guess it's a totally accepted thing with those guys. "
I think you ran into the minority. I think most vette owners will agree that stock includes tires, exhaust.
One of my favorite sayings is "Stock to the paper air filter!"
Either way OP, good kill! Way to put the cocky owner in his place. Too bad he had a ZR1 though.. That car deserves a better owner ! :-D