I know with the Fiourduh's, the half ton was an F-100. The heavy half would be a F-150.

My 59 GMC is a 100. They have 150's on up. I would "assume" that the 150 would be a heavy half.

Help me out guys.

Chevy has 3100 which is half/shortbox, and 3200 which are half/longbox. A 3400 is 3/4.