Not sure where you are in the process. So I'll write as though all uses of the rope are considered.

1. Belt broken. Cam and crank have no relationship. Top timing cover removed, place timing mark on cam gear in alignment with mark (around 11:30). Place damper exactly opposite of TDC mark. Insert rope. Rotate crank CCW. Rope will stop rotation near 20 degrees ATDC (depending on how much rope of course) then you can break the crank bolt loose.

2. Belt still OK. Start with cam gear at mark. Rotate crank CW until damper is 180 like above. Insert rope. Return crank CCW to stop and break loose.

3. All done, new belt in. Dress inside of damper and outside of crank to clean off surface rust. Lube it with whatever's handy so you can twist the damper on the crank without the friction turning the crank. This way you'll know when the key is locked in place and it is safe to turn in the bolt.

Using the ratchet, snug the bolt just enough so you can use it to back the crank CCW past TDC (help it with a hand on the cam gear) until it is 180 out like above. Insert rope. Begin turning it CW again. Check damper mark position when the rope stops the movement-- should be about at the 20 BTDC advance mark on the cover. Check the cam gear alignment mark. Should be around 10:30-11:00 to the left of the mark on the cover. Torque to spec.

Note: If you're looking for the cam position with the cover in place over the gear, the easiest way to find it is placing your thumb over the spark plug hole to feel the compression building as you approach TDC. This will be as accurate as putting a wire in the opening, and you will be confirming the cam is positioned for compression stroke.

--
Art Benstein near Baltimore