The Chevrolet Task Force followed the Advance Design beginning in late 1955 and ran through 1959. The Apache, Viking, and Spartan (light, medium, and heavy-duty, respectively) trucks were a big step forward with new offerings such as GM's first V8 engine and a 12-volt electrical system.

Decades of time are generally not kind to mounts and rubber. It’s probably time to go ahead and replace them with some brand-new pieces to give you that peace of mind.