I was talking to a gentleman I know that has been a truck driver for the last 60 years. I was asking him about the "double-clutching" topic. He taught me to drive truck years ago and with some practice you always have it. Anyway, he was telling me that the toughest truck he ever drove was a '52 Ford F-7 firetruck with a Lincoln OHV motor and a 5 speed. He said that you could'nt shift that truck without using the clutch and double clutching it. He said no matter how much you tried you could never shift it up or down without the clutch.