1991 REAR AAXLE IDENTIFICATION A MODEL CODE RATIO SIZE BRAKE OPTION MODEL CODE RATIO SIZE BRAKE OPTION V L1 SGH 3 42 7 625 9 5 X 2 EXC G60 L1 SGJ 3 42 7 625 9 5 X 2 W GSO L1 V SGK 3 73 7 625 9 5 X 2 EXC GBO L1 SGL 3 73 7 625 9 5 X 2 W G80 L1 SGU 3 42 7 625 9 5 X 2 EXC G80 L1 SGW 3 42 7 625 9 5 X 2 W G80 L1 SGX 3 73 7 625 9 5 X 2 EXC GSO L1 SGY 3 73 7 625 9 5 X 2 W G80 M1 SGF 3 23 7 625 9 5 X 2 EXC G80 M1 SGG 3 23 7 625 9 5 X 2 W GBO M1 SGH 3 42 7 625 9 5 X 2 EXC GSO M1 SGJ 3 42 7 625 9 5 X 2 W GB0 M1 SGK 3 73 7 625 9 5 X 2 EXC G80 M1 SGL 3 73 7 625 9 5 X 2 A W G80 M1 SGM 4 10 7 625 9 5 X 2 EXC GSO M1 SGN 4 10 7 625 9 5 X 2 W GSO M1 SGS 3 23 7 625 9 5 X 2 EXC GBO M1 SGT 3 23 7 625 9 5 X 29 W G80 M1 SGU 3 42 7 625 9 5 X 2 EXC 680 M1 SGW 3 42 7 625 9 5 X 2 W G80 M1 SGX 3 73 7 625 9 5 X 2 EXC G60 M1 SGY 3 73 7 625 9 5 X 2 W G60 M1 SHL 4 10 7 625 9 5 X 2 EXC G80 M1 SHM 4 10 7 625 9 5 X 2 W GB0 Y 1991 GENERAL MOTORS SERVICE PARTS OPERATIONS LTTRUCK 52M 5 386 A 5y A 1 91