I wondered about this myself. The Corvette drove like the one I now own so that was not restricted in any way but the GT500 could not really be tested properly. Great straight line speed though!
I meant it was turned on and the switch was disabled so you could not turn it off and have some...
I rented the GT in Houston for a couple of weeks and was disappointed as it had the traction control button disabled, so not a huge amount of fun to drive. I few months later I rented the Corvette and had a blast, quite literally. Thought I was in for it when I was doing doughnuts in the hotel...
Probably an extra 3-4 inches but I prefer that you can simply lift it to the cut off point and not have to worry.
I also have a MD-6XP which I use for track days but if it is at all possible, get a 2 or 4 post lift for home, I could not live without mine now.
This might help in working out heights.
Source = Pickup World
As you can see, with the new Benpak models, you can get away with less than 9" but you will still need decent concrete to secure the lift so depending on what you want to work on, size wise, this should give you some decent options...