[George/Maine]

I test the old way Take the wire end out of cap and hold 1/4" to ground. With key on turn over with starter should spark ever time for each cylinder.
The flat head is about the only engine that the valves are not adjustable. Unless they have been changed to adjustable. You want TDC when NOT firing.
When you find TDC turn crankshaft 1/4 turn for each cylinder ,2 times for 8 cylinder.