There are about 20 different side cover configurations for those transmissions depending on year, car, or truck application. Some have different shaft lengths on the 2/3 and 1/R posts and clocking position depending on the vehicle it was designed for. I suggest you use the side cover from the transmission you removed. Also be aware that the 2/3 shift fork is a high wear component, it would be a good idea to replace it.
Fred
