I think he's just talking about replacing what he's going to lose by tipping the trans. I guess I can't suggest using a slip plug and keep all the fluid in it. Since you won't have a slip yoke once you pull the Tcase off. Since you do have a Tcase, you could pull the trans and Tcase as a unit, then pull the motor by itself.
At any rate, if you bought that Super Tech Blue gallon Jug at Wally World for about $11, that should do it. You could also drop the pan slowly on one side and catch what comes out of the pan into a clean oil pan and reuse it, if it's a pretty color. As expensive as fluids are these days, I reuse all I can of trans fluid. If it's nice and red, (Not Maroon or Brown), I catch, using a funnel with a strainer, I pour it back into one of my empty Gallon ATF jugs that is marked 'USED". That's also what I use to mix with Acetone to make my penetrating oil out of.