Hello everyone. I'm new on here as I'm currently in the market for an 2000's Mustang GT. I have a lead on a 2000 GT and a 2003 GT convertible. 80k miles each and both are autos. they are asking 6K each. I plan to have fun on the street and hit the track when I can. It will be a toy that I drive. I'm thinking I'll be adding 4.10 gears, a converter and shift kit. Are 4.10 gears good with an auto? What stall works best with these cars with 4.10 gears, if the gearing is even good? Also, how do I calibrate the speedometer after the gear change? And another question, what is the largest tire that fits on the rear with the stock rims? Thanks!

 

the 2003 convertible is a centennial edition. I'm not sure that means much.