you MUST keep in mind that when you put a different size tire on the car, the overal diameter must be very close to the overal diameter of the original tire. 214/40/16 WILL NOT FIT an svt. You will screw up your car if your tires is larger or smaller than the stock size to a certain degree. LArger is worse than smaller, but i still wouldn't go that small. Your overal diameter should be somewhere in between 23.7 and 24.8 on a 99 svt, given that the computer is calibrated for bf goodrich's 24.3. I know a good bit about tires and have worked with many tire dealers. I've faced the same problem you have, and the only true solution is to switch to 17" rims which is probably what i'm gonna do, even though i really like the stock 99 rims. Just my .03 cents
