My wife and I just bought a 2005 Convertible Roush 4.6L and I am looking to replace the stock wheels and tires. They are currently 17" Wheels with 235/55R17 tires. I am thinking I want to stay with the same total diameter. I would like to go with 18 or 19 inch wheels and a tire that would yield the same height as stock. I was also thinking I could go a little wider in the back, so I am looking for information on how wide I can go without issues and what size tire with a 18" or 19" wheel.