CORVETTE ENGINE SERIES NUMBER AND SUFFIX CHART Cont 1980 TRANSMISSION IDENTIFICATION CODES M18 4 SPD MAN ZJ M33 3 SPD A T JC BUICK MV4 3 SPD A T T N CHEV 1980 TRANSMISSION IDENTIFICATION CODE NI18 4 SPD MAN NIX3 3 SPD A T CC 8JD WAREHOUSING AND DISTRIBUTION DIVISION OF GENERAL MOTORS CORPORATION CHEVROLET 14 16