Just to add to this, the hand throttle could be had on trucks up to at least '72. Usually on the later trucks, it'll be found with a 4 speed with a pto operated accessory, like a pump or winch. GMC had a pto winch as an option up to '72 on 4x4 models. I do know a local guy with a '72 chevy C20 with the throttle cable on a V8 with an auto trans. We both throught it was odd, but there it was. This truck has another odd option as well, the 3.54 rear end gear in the Eaton diff.
