[1968 Pontiac]

I found it's easiest to pull both together, then disassemble and switch outside the vehicle. I have a plate that bolts to the carb opening on the intake. With the tranny attached, the assembly is balanced nicely, tilting down slightly at the back for easy removal. If you have a spare yoke put it in the back of the tranny so you don't dump the tranny fluid out the tail shaft.

If you removed the engine/tranny as an assembly, before you put the assembly down to the ground, remove the inspection cover from the bottom and remove the three bolts which fasten the torque convertor to the ring gear. At this point I drop the assembly down, leaving the engine dangling and supporting the tranny with some wood blocks under the pan. Then, undo the six bolts which hold tranny and engine together. The tranny dip stick tube should be fastened with one of these bolts. Once it's fee, pull the tube out of the casting and stuff the hole with a rag. There are also two dowels aligning the engine and tranny which are sometimes difficult to separate. Once you start to get the assembly to separate, make sure the torque converter stays on the tranny shaft, 'cause if it falls off you'll have tranny fluid all over the place and risk contaminating the fluid in the torque convertor.