A TRUCK TRANSMISSION PRODUCTION CODE EXPLANATION Continued MUNCIE TRUCK 4 SPEED Stamped on the rear face of the transmission case below the rear retainer The production code number contains the source code mode1 year and build date EXAMPLE N H A 10 A SOURCE CODE MODEL YEAR BUILD MONTH DAY CODE N 4 Speed 1985 A Jan K Ju1 10th A Muncie B Feb M Aug A CH465 C Mar P Sept D Apr R Oct I E May S Nov H Jun T Dec 350 MODEL TURBO HYDRA MATIC TRANSMISSION V The production code consists of the source code followed by the model year mont date and shift produced EXAMPLE B H K A 05 D SOURCE CODE MODEL YEAR MONTH CODE DAY CODE SHIFT CODE B Parma 1985 A Jan A 5th D 1st Shift Y Toledo B Feb N 2nd Shift J GM of Canada C Mar D Apr E May H Jun K Ju1 M Aug P Sept R Oct S Nov T Dec The identification number is stamped on the right side of the transmission oil pan r l 1988 GENERAL MOTORS SERVICE PARTS OPERATIONS LT TRUCK 52R REV 1 88 25