Use a piston stop to confirm TDC on #1 cylinder and to properly index a timing tape marked every 90 degrees. Take the valve covers off to check rockers to see that the valves are closed on each cylinder at TDC on each cylinder.
I was 14-15 at the time. My attention was on girls and cars so wasn't paying attention to everything being said or shown.
But the main thing would be #1 at top dead center to start the show. Then checking for tdc on #6 without changing the initial setting of The harmonic balancer and cam relationship.