GM Getrag 5sp 1st Design Transmission Rebuild Kit for the 1988-89. BK235 MG5, HM290 Transmission Rebuild Kit This complete kit includes wide front and rear main shaft bearings, input pocket bearings, complete small parts kit which includes snap rings, washers etc. and seals Identify this transmission by an Aluminum Case, Rear Load. 1st Design. The transmission uses wide (1.30") Input and Output Bearings and Countershaft Bearings that are 1.020" Inside Diameter.