nearly everything from 55-59 interchanges, the difference being that the 58-9 frame is 1/2" longer for the 'gravel pan' right behind the bumper, and the 58-9 front sheet metal is different from 5-7 and the hood hinges mount differently to the cab and inner fenders - 58-9 are entirely interchangeable, the only difference being the trim on hood and fenders, and grill between GMC and Chev - the box is identical 55-66 except for the Chevrolet or GMC on the tailgate - the only cab difference is Chev and GMC dashes and gauges differ
Bill
