Just arrived at home.
The car (and the transmission) work perfectly.
The Inland shifter isn't so bad... Maybe that this transmission didn't work a lot during its history and the shifter mechanism isn't too much loose (I've known worst with some european cars :D).
As the 833 comes from a '66 Barracuda 225cid, the 4 gears ratios are well adapted for my /6 and the car is a little bit more nervous :)