Regarding the two piece rotors, I can remember that a company offered these using Porsche rotors on a Corvette message board. They were initially sold as assembled and disassembled. However, they mentioned that in assembling, the finished product must be checked for run-out. With the Racing Brake design, they indicate that reversing the hats let them use the same rotor from side to side and that the rotors can be swapped from a 24mm to a 28mm size, depending on application. Are any special procedures recommended to insure that, reversing the rotor hats, or changing the rotor thickness, they run straight and true?