1987 FRONT AXLE IDENTIFICATION I A V M0DEL CODE RATIO I T1 ZAA 3 42 T1 ZAB 3 73 T1 ZAC 4 11 1988 FRONT AXLE IDENTIFICATION MODEL CODE RATIO I T1 ZAD 3 42 T1 ZAH 3 08 V T1 ZAK 3 42 T1 ZAL 3 73 I T1 ZAM 4 11 1989 FRONTA AXLE IDENTIFICATION MODEL CODE RATIO T1 ZAD 3 42R T1 ZAH 3 08R T1 ZAL 3 73R I T1 ZAM 4 11R h 1990 FRONT AXLE IDENTIFICATIONE A MODEL A CODE RATIO T1 ZAD 3 42 A T1 ZAH 3 08 iii 1990 GENERAL MOTORS SERVICE PARTS OPERAT ONS LT TRUCK 52S 6 008 I 6 4 REV 10 90