I have 8v71 and 740 and only High switch Jake.
this bus is my only experience with all.
I use the Jakes to maintain "slow" down a hill and not necessarrally to stop. I use brakes to stop.
I usually find that there is a speed that it will maintain and above that it will start speeding up.
I'm not sure how mine are wired up, however they cut out at a really low speed, and as far as the torque convereter. Mine does not seem to unlock until a certain low speed in first. I.e. locks after shifting into second on the way up and un-locks in first on the way down.
Just my 2 cents, skewed as it may be