In 1973, Chevrolet presented an updated medium duty range. The trucks received a new tough, injection molded, one-piece plastic grille. The new massive front bumper provides increased surface area and strength. The customer could choose between a new alligator hood design and fiberglass tilt hood design. An alligator-type hood design provides access for routine maintenance, inspection or servicing of the engine or other components completely located in the engine compartment. Entire hood can be quickly removed by sacking out only four bolts. A tilting fiberglass hood of the same design was an extra cost option. The standard glass area has been increased 19% (from 2460 to 2931 square inches). The available full width rear window will more than double rear glass area. The new door frame is fabricated from a single piece of a sheet metal. The front fenders are also received an-all new design. Chevrolet's compact 97.5" BBC allowed big payloads, good weight distribution, and easy of maneuvering. Deluxe two-tone paint with white and a choice of 11 second colors was available as an option. Inside the cabins was the absolutely new exterior. Several engines were available: 250 Six rated at 100 hp, 292 Six at 130 hp, 350 V8 at 160 hp, 366 V8 at 200 hp and 427 V8 at 230 hp. Since 1977, the four cylinder Detroit Diesel 4-53 was available.
Series 50 had wheelbases from 125 to 167 inches for a wide range of applications. Standard components included in-line Six or V8 power, depending on model; 4-speed transmission; 5,000-lb. front axle and 11,000-lb. rear axle. GVWs from 13,500 to 18.500 lb.
Series 60 had wheelbases from 125 to 218 inches. Engine availability: Six of V8. Standard: 5,000-lb. front axle, 15,000-lb. rear axle with hydraulic brakes, 7000-lb. front, 17,000-lb rear with air. GVWs from 16,000 to 24,000 lbs, GCWs to 45,000 lbs.
Series 65 had wheelbases from 125 to 218 inches. Standard specification included V8 power, 4-speed or 5-speed transmission, 7,000-lb. front axle and 17,000-lb rear (except ME65 with 30,000-lb. tandem rear axles). GVW from 21,000 to 40,500 lbs, GCWs to 60,000 lbs. Tandem rear axle models ME65 were available with 149-185 inches wheelbases and still used Hendrickson components.
Series 70 was available from the end of 70s with GVW to 33,400 lbs for single rear axle model, and up to 50,000 lbs for tandem.