Yes, that is the idea, the spark plugs must be removed. You have the spark plug wires in the cap, then ground each one. I rigged up a harness of 8 big alligator clips that I use to ground each wire. I do this a lot so it made sense to rig that up. But in a pinch I just stick the spark plugs into each wire and lay them on the intake manifold. Or wrap some soft copper wire around each plug base and ground that. That way the spark is grounded. You can't just leave the wires un-grounded because electricity will find it's own ground. The end result is usually a blown ignition module. So with all the wires grounded, the ignition can fire normally, and the #1 wire will light up the timing light when it does. Loosen the distributor so it can be turned. Have a helper, or use a remote start button, to crank the engine. It will spin fairly rapidly because there are no plugs in, so no compression to fight against. The timing light will light up when #1 fires and you turn the distributor until the timing is right on, at 9°. If the timing is not even close then you are not working off #1 at TDC. If OK then tighten the distributor. Double check and if OK, you are done. It sounds more complicated than it is, but try it and you will see it is very simple. What you are doing is spinning the engine as if it was idleing. But it will never spin fast enough for the centrifugal advance to give a false timing event.
