Hi Maxie,
The best way I've found to remove the 4 spd gearbox form my
'28 LP truck,is as follows:
Remove battery,floor boards,pedals,drain gearbox etc first.Then remove the front brake cross shaft and the bracket that attaches to the rear of the gearbox.Then unbolt the uni - joint ball housing retainer,and slide the uni-joint housing as far back down the torque tube as it will go.
Remove the handbrake lever and the gearstick as well.Split the uni-joint(unbolt the clamps rings if they are are bolted),push the tail shaft yoke,bushes and half ring down inside the ball housing,and with a floor jack and some packing under the torque tube,lower the torque tube as far as it will go down.
Then remove the the 2 bolts & nuts along with the packing shim on either side of the cross member that's fitted between the clutch housing and gearbox casing.If you have a helper about,you should then be able to juggle the whole gearbox/clutch housing rearwards,and down.Just watch your back - they're damn heavy.
This way you'll be able to leave the engine in place,because to remove the whole engine/gearbox assembly as a unit will be a REAL headache,unless the cabin is off your chassis.I tried to remove everthing in one go once,and found that the flywheel will not clear over the rear engine cross member,as the cabin was still on my chassis.
Hope this helps you out.