The truck the man facing toward the camera (wearing the light colored hat) is leaning against is an early 60's model Chevrolet. I can tell by the way the stepside bed has the little ridge above the wheels on the fenders.

On the larger picture, you can see that the license plate is a blue background plate, which would mean it was an odd numbered year (61, 63, 65, etc), as back then we got a new plate every year, at least until 1975, and odd years were blue background and even numbered years were white background.