I ordered motor mounts and wheel cylinder to my 80' Z28 and it doesn't fit. The dealer costumer service told me that the motor mounts I ordered are for camaro with High-Pref and the wheel cylinders are for export camaros. what are the difference with the exports and what high pref mean? I know that my Camaro sold in the states and I thought that the Z28 is the high pref for 1980. Am I wrong or it just that the last owner swapped to a different engine then the stock 80 Z28 and changed the wheel cylinders?