1985 REAR AXLE IDENTIFICATION MODEL CODE RATIO SIZE BRAKE MODEL CODE RATIO SIZE BRAKE 1 M1 FAA 2 56 7 50 9 5 X 2 A EXC G80 M1 FBA 2 56 7 50 9 5 X 2 I A W G80 M1 FCA 2 73 7 50 9 5 x 2 EXC G80 M1 FCB 2 73 7 50 9 5 X 2 W G80 M1 FFA 3 08 7 50 9 5 X 2 EXC GBO M1 FFB 3 08 7 50 9 5 X 2 W G80 M1 FMA 3 42 7 50 9 5 X 2 EXC G80 M1 FMB 3 42 7 50 9 5 X 2 W G80 A M1 FRA 3 73 7 50 9 5 X 2 EXC G80 M1 FRB 3 73 7 50 9 5 X 2 W G80 M1 FSA 4 11 7 50 9 5 X 2 EXC G80 M1 FSD 4 11 7 50 9 5 X 2 W G80 M1 GWH 4 10 7 50 9 5 X 2 EXC G80 M1 GWJ 4 10 7 50 9 5 X 2 W G80 1986 REAR AXLE IDENTIFICAT ION MODEL CODE RATIO SIZE BRAKE A MODEL CODE RATIO SIZE BRAKE M1 FCB 2 73 7 501 9 5 xL2 W G8O M1 FAA 2 56 7 50 9 5 X 2 EXC G80 M1 FFB 3 08 7 50 9 5 X 2 W G80 M1 FCA 2 73 7 50 9 5 X 2 EXC G80 M1 FMB 3 42 7 50 9 5 X 2 W G80 M1 FFA 3 08 7 50 9 5 X12 EXC G80 M1 FBA 2 56 7 50 9 5 X 2 W G80 M1 FMA 3 42 7 50 9 5 X 2 EXC G80 M1 FRB 3 73 7 50 9 5 X 2 W G80 M1 FRA 3 73 7 50 9 5 X 2 EXC G80 M1 GWJ 4 11 7 50 9 5 X 2 W GSO M1 GWH 4 11 7 50 9 5 X 2 EXC G80 M1 FSD 4 11 7 50 9L5 X 2 W G80 M1 FSA 4 11 7 50 9 5 X 2 EXC G80 I M1 HZF 3 73 7 50 A 9 5 X 2 W G80 M1 HZG 4 11 L 7 50 9 5 X 2 W G80 I A 1987 REAR AXLE IDENTIFICATION A MODEL CODE RATIO SIZE BRAKE MODEL CODE RATIO SIZE BRAKE M1 FCA 2 73 7 50 9 5 X 2 EXC G80 M1 HZA 2 73 7 50 9 5 X 2 W GSO v5 M1 FFA 3 08 7 50 9 5 X 2v EXC G80 M1 HZB 3 08 7 50 9 5 X 2 W G80 M1 FMA 3 42 7 50 9 5 X 2 EXC G80 M1 HZC 3 42 7 50 9 5 X 2 W G80 1 M1 FRA 3 73 7 50 9 5 X 2 EXC G80 M1 HXF 3 73 7 50 9 5 x 2 W G80 M1 GWH 4 10 7 50 9 5 X 2 EXC GBO M1 HZG 4 10 7 50 9 5 X 2 W G80 M1 KJM 2 73 7 50 9 5 X 2 EXC G80 M1 T KJR 2173 7 50 9 5 X 2 W G80 M1 KJN 3 08 7 50 9 5 X 2 EXC G80 M1 KJS 3 08 7 50 9 5 X 2 W GSO M1 KJP 3 42 7 50 9 5 X 2 EXC G80 M1 KJT 3 42 7 50 9 5 X 2 W G80 M1 KJU 3 73 7 50 9 5 X 2 EXC G80 M1 KJW 3 73 7 50 9 5 X 2 W G80 M1 KJX 4 10 7 50 9 5 X 2 EXC G80 M1 KJY 4 10 7 50 9 5 X 2 W GB0 M1 KRK 2 73 7 50 9 5 X 2 EXC G80 M1 KRN 2 73 7 50 9 5 X 2 W G80 M1 KRL 3 08 7 50 9 5 X 2 EXC GBO M1 KRP 3 08 7 50 9 5 X 2 W GSO M1 KRM 3 42 7 50 9 5 X 2 EXC G80 M1 KRR 3 42 7 50 9 5 X 2 W G80 M1 KRS 3 73 7 50 9 5 X 2 EXC G80 M1 KRT 3 73 7 50 9 5 X 2 W G80 M1 KRU 4 10 7 50 9 5 X 2 EXC G80 M1 KRW 4 10 7 50 9 5 X 2 W G80 A A I A 1988 REAR AXLE IDENTIFICATION MODEL CODE RATIO SIZE BRAKE MODEL CODE RATIO SIZE BRAKE A M1 FAF 2 73 7 50 9 5 X 2r EXC GBO M1 FAJ 2 73 7 50 9 5 x 2 W G80 M1 FAG 3 08 7 50 9 5 X 2 EXC G80 M1 FAK 3 08 7 50 9 5 x 2 W G8O M1 FAH 3 42 7 50 9 5 X 2 EXC GBO M1 FAL 3 42 7 50 9 5 X 2 W G80 M1 FAM 3 73 7 50 9 5 X 2 EXC G80 M1 FAN 3 73 7 50 9 5 X 2 W G80 A M1 FAP 4 10 7 50 9 5 X 2 EXC GBO M1 FAR 4 10 7 50 9 5 X 2 W G80 M1 FAS 3 23 7 50 9 5 X 2 EXC G80 M1 FAT 3 23 7 50 9 5 X 2 W 680 A L J 1991 GENERAL MOTORS SERVICE PARTS OPERAT ONS LTTRUCK 52M 5 386 5 6 1 91