Harmonic balancer tightening (crank bolt) engine in car with 4spd manual transmission

In my younger days;
I would put my big 1/2 drive Johnson-bar on there, put the bar on the frame, and hit the starter. Bam!, the bolt was loose, and the bar was on the ground.
Obviously, you can't tighten it that way, but if I could I would.
But what I have done is put a bar on the flywheel to anchor it to the bellhouse.
Using the manual trans is an idea, but to prevent the car from moving, you'll have to set the parking brake to lock it up. Which means that when you go to tighten the bolt, the torque will go into; the backing plates, then the banjo, then the springs, and you will be winding all that up until the snubber hits the floorpan, before any torque goes into the bolt. Ergo, it will take some extra swinging room for the bar.
Whereas the bar in the ring-gear eliminates all that .................... as does Rusty's method.