I TP06 321 RPO DEFINITIONS I F66 SUSPENSION HEAVY DUTY FRONT AIR JB7 BRAKE SYSTEM VACUUM POWER DISC DRUM JB8 BRAKE SYSTEM HYDRAULIC POWER D SC DRUM J JD7 BRAKE SYSTEM HYDRAULIC POWER DISCQDRUM I I JF9 BRAKE SYSTEM HYDRAUL C POWER 4 WHEEL DISC V LL4 ENGINE 6 2L 6 2J DIESEL V8 LO5 ENGINE 5 7L 5 7I V8 DIGITAL FUEL INJECTION V RO5 WHEELS DUAL REAR I 9LG SUSPENSION SYSTEIVLFRONT REAR LOW POS TION H EAVY DUTY xi I992 GENERAL MOTORS SERVICE PARTS OPERAT ONS LT TRUCK 53P 6 000 GROUP 6 32 9 92