CHASSIS S10803 118 4100 JB1 STD JM7 J50 I S10803 118 4100 JM7 J50 S10803 1 18 4600 JM5 STD 1983 BRAKE SYSTEM USAGE CHART I T TRUCK I I A VEHICLE SPECIFICATIONS BRAKE SYSTEM ... T10803 118 4100 JB1 STD JM7 J50 T10803 118 4100 JM7 J50 A I T10803 1 18 4600 JM5 STD WAREHOUSING AND DISTRIBUTION DIVISION OF GENERAL MOTORS CORPORATION LT TRUCK