On the 1/2, 3/4, and 1 tons, the small rear window was a standard feature during 1967. A large panoramic rear window cab was an extra cost option.
Beginning in 1968, the small rear window cab was discontinued except in the 60 series two ton. In this larger truck the small window continued to be standard through the end of 1972.
Thus, when you see a small window light truck in the distance, you can feel sure it is pure 1967!