Those gears are kinda square (yours are probably round by now-LOL) and you will have a hard time shifting down at 40mph and trying to use the engine for a brake. You need to have "three feet"- one for the gas, one for the cluth and the other to hit the brake to help slow you down. You will be revving your engine plenty hard to be able to shift down at anything over 15 or 20 mph, they are really low geared. I have driven many of these old rigs with out a cluth linkage. Makes for fun to start them in gear. But I don't like driving them without brakes.
Oly in Oregon
Rest in Peace1945 GMC COE Victory Truck
1953 Willys CJ3B
1955 Chevy 1st series 3/4-ton
1958 WIFE Last series
Never say "Whoa" in a mud hole