How Hard would it be to get Vette Wheels 99 style to fit on a thirdgen? how much work would need to be done to make them fit?

 

Just money for the spacers and they should fit unless you plan on some ultra wide wheels.

 

There are a few of us on here running these, including myself, so it is nothing new. I am running the 18x9.5s all around with 275/35/18's and they fit fine. I had to hammer one spot in each rear wheel well but it was literally 2 or 3 hammer blows. Do a search and you can find pictures and spacer recommendations. If you want to run 17" c5s all around I have a set for you if you are interested.
Tyler

 

18's do look nicer but they you have the larger offsets and tires are extremely expensive. my 18" z06's were a fortune.

good luck.