Personally, it seems to me to be an extra part to go wrong. If you can run the gas pedal with enough discipline to keep the speedo at 60 mph or less, you dont need one. It was handy in the military due to younger soldiers, 18-20 year olds especially, who were driving their first vehicle...well someone elses vehicle they didnt have to pay for or pay to fix......
If you have enough hose to fit between the metal piece on top of the carb and the underhood canister air cleaner housing, use that and dont bother to change to the cabr mounted style...course maybe you like the other one OR the cost of replacement filters is so much less that it is worth swapping on that count...but it should work with either one.
If you are going for CORRECT for your truck, put on the governor...though early trucks didnt have them and some later trucks didnt either...no one has a list of which did or didnt...the only tip off would be the underhood aircleaner on a non governor truck...otherwise, only you would know.