LONG before Chevy used the Silverado or C/K-series nomenclature, the company used a more confusing four-digit code to break their trucks into light-duty, medium-duty and heavy-duty models.
From 1947-1962, General Motors trucks were arranged by size into the 3000, 4000, 5000 and 6000 ranges, from simple, quarter-ton farm trucks to the high-riding, heavy-duty tray-back machines you’d see hauling produce or steel, or a box-back for cargo-carrying.
The huge heavy-duty machines featured larger chassis, drivetrain and suspension to cope with the industrialsized loads they were rated to carry, and this can make turning them into fine-driving street machines a much bigger job than starting with a light- or mid-duty truck. However, as few light- and medium-duty pick-ups survived their life as work vehicles, punters have taken to grabbing the cabs from…