I would be very concerned about weight carrying capacity being reduced. Corvette's already have passenger and cargo weights around 550 LBS. If you reduce the wheel size, keep the aspect ratio the same, the air chamber gets even smaller and weight capacity get lower. You also have to deal with different steering characteristics of the vehicle. If you change impacts the overall diameter of the tires everything based on vehicle speed, is impacted. This include A8 shift points, ABS engagement points, traction control, etc. If you keep the overall diameter the same then the handling will get significantly worse because will introduce increased sidewall flex. They are 1 inch taller after all. Other than track in some very specific situations I would do some serious research before I made this shift.