The most significant improvement for 1964 was the change from the dogleg windshield to the conventional curved type. It provided easier entrance and exits for driver and passengers and looked much better too. In 1964, the range included 6 gasoline series C50, C60, C60-H, C80 (single axle), M60 and M80 (tandem axles) and 2 diesel series D60 and D60-H. But in 1965, the company presented a wide range of diesel models.
The new D50 model cover the GVW range from 10,000 to 20,000 lbs., powered by the Chevy-GM-Detroit 3-53N engine, previously available only in export models. Also in this weight class were new Q50 models in a full range of sizes, powered by the new D-351 Torq-Flow Diesel, and for heavier duty there were new Q60, Q60-H and Q80 models with 478-cu. in. Torq-Flow engines.
And all these were in addition to the proved D60 and D60-H models, equipped with updated higher performance Chevy-GM-Detroit 4-53N engine. The variety of optional equipment was available – new intermediate rear axle capacities for Series 50 and 60, and a new 5-speed transmission option for Series 60.
New trailing-axle models in 30,000 lbs. GVW class were V60 models, powered by D-478 or DH-478 Torq-Flow Diesels, and X60’s with new higher output Chevy-GM-Detroit 4-53N Diesel engines. In the dual-drive tandem line, there was the new V80 Series with DH478 Torq-Flow Diesel in both vacuum- and full-air-brake models.