MODEL IDENTIFICATION C0nt d MODEL TRUCK MODEL ENGINE FRONT REAR TRANSMISSION YEAR AND WHEEL BASE TYPE CLUTCH AXLE AXLE STD OPT 1974 5AC80 350 2 SE 10 1FS019 HO27 SM326 AT400 5AO80 W Opt 350 4 SE 10 SM326 AT400 Opt 400 2 SE AT40O Opt 400 4 SE AT400 Opt 454 4 DE 11 SM34O AT400 1975 5AC80 250 1 SE 10 1FS019 HO27 SM326 AT400 5AO8O 350 2 SE 10 SM326 AT400 Opt 3504 SE AT400 Opt 400 4 SE AT4OO Opt 454 4 SE AT4OO 1976 5AC80 250 10 1FS019 H028 SM326 AT400 5AD80 1 ATAOO 305 2 AT40O 350 4 AT400 In 1t4 1977 5AC80 250 10 1FS019 H028 SM326 AT4OO 5AD80 Ki AIAUO Ki AIAOU GM PARTS DIVISION GENERAL MOTORS CORPORATION SPRINT 57 4