GMPartsGiant.com offers the wholesale prices for genuine 1990 Oldsmobile Cutlass Supreme Base parts. Parts like Automatic Transmission Case Cover And Components are shipped directly from authorized GM dealers and backed by the manufacturer's warranty. Parts fit for the following vehicle options. Engine: 4 Cyl 2.3L, 4 Cyl 2.5L, 6 Cyl 3.1L, 6 Cyl 3.3L. Model Code: 2 DOOR, 4 DOOR.