I happened across a '56 F600 for sale the other day and have only talked to the owner via email. He says it has a 292 and 3 speed. I asked if he meant 3 speed w/ granny (4 speed) and he said no, that it was a 3 speed. All I have read about the big trucks from the mid fifties would indicate it should have a 4 speed. Any thoughts?

 

My friend has a fleet of 50's F600's and they are all 4 or 5 spd, some with 2spd rears. Ive never heard of a 3 spd in one.

However a HD 3sd was offered in smaller models and may have been swapped in OR the guy cant find one of his gears

 

I don't know if this applies to the 53-56 trucks but for the 48-52 trucks a F-6 school bus had the option of the 3 spd heavy duty.