First thing you want to look for is the # on the passenger side of the rear of the case just above the oil pan on the case itself. The FIRST digit denotes to year model of the transmission. NOTICE - First Digit 9 Denotes Both 1982 Model, and 1989 Model. There are 2 ways to determine a 1982 Model and a 1989 Model. #1 82 has 2 letter code, 89 has a 3 letter code. #2, 82 will have pressure taps, 89 will NOT.