To OP,
If you notice in many of the pics, where the installer has his rear jack stands located heavily influences how much weigh the hoist (and front chassis) has to support. Mine were placed just at the rear spring front perch bulkhead. Some have placed theirs at the axle tubes, which adds to the weight that must be lifted at the front. The rear jack stand location is the "balance point" of the teetering assembly, if you will. ('72 RR, btw).

With jack stands at the front spring perch bulkhead, I put about 700-800 lbs of concrete landscaping blocks in the trunk to minimize the weight at the front to be lifted. In fact, there was enough weight in the trunk to allow me to lift the front of the car with one hand. To prevent over-rotating the car onto the rear bumper, I placed another jack stand under one of the rear arches of one of the leaf springs.

The hood stayed on. The front bumper stayed on. Even had the front control arms on also, though I can't remember if the front discs were also, as I was working on the brakes before I got the engine back from the builder.

With car rotated up, engine and trans went under easy as you please. Lowered car onto dolly/engine/trans. Minimal weight on front allowed rejiggering of dolly to align frame rail/K-frame holes. Fortunately, K-frame angle on dolly (just slightly nose-down) plus flex in motor mounts allowed all four bolts to go in without trouble.

11' ceilings at that garage, but front was under garage door at 8'. Still had enough room (with hood closed) to get front high enough to roll engine under.