WE b OLD: A 37 has a top load floor shifter. It is possible for the forks to get "locked", but it is not like a column shifter where the levers get jambed up and malfunction. A floor shifter will lock up and not shift.
George: My 37 has 54 gears in it except for the out put shaft because it has ten splines and my truck drive train is basically a ten spline drive line. Your 46, I believe, has a 17 spline output.
It does help the drivability of the truck. The only thing I had trouble with when I did this was with bearings. I replaced all of the bearings in the transmission and I had trouble finding a few of them. I sold a new house to a guy that was a rep for some bearing company, though, and he ended getting what I needed. I think if you went to one of the larger bearing houses, you could get what you needed.
Another critical thing is the transmission case. Some of the bearings run in races machined into the case and if those are bad or worn, you will be looking at finding a new case. I was lucky and mine were OK and yours probably are too, but it's something to be aware of.
Now the final question: I don't know if the gears in your transmission are cross cut or straight cut. Maybe someone her can tell us, like wdfoftx or Barry Weeks. My guess is that they are crosscut and you have good gears already. That's not to say that a set of 54 gears wouldn't help your transmission.
Joe
