Does anyone know if there is a way of determining prior to mounting a new Starter Motor, if the Starter Motor needs to be shimmed or not. I didn't know if there is a measurement or something similar that could be checked prior to installation. I am installing a new T.C.I. High Torque Starter on the 455 Engine I am rebuilding. When I took the motor out of the car and unbolted the old original starter, there were numerous starter shims being used, equaling between 3/16 and 1/4 inch. I am trying to determine whether or not it is "a given" that these same shims would need to be re installed. I am trying to determine prior to assembly as the shims would be easier to install now versus once the engine is back in the car. When I measured the thickness of both the old and the new Starters Mounting Surfaces where the two mounting bolts run through, both Starters measured 3 5/8" thick. I have never myself had to use shims with a starter but I know it is common to have to use them sometimes. This is why I am unfamiliar with what really determines whether or not they are needed. Any help appreciated.