You bring the engines #1 piston TDC on it's compression stroke. If the rotor is not pointed at the 7 O'clock position the oil pump/distibutor are not indexed properly. If #1 plug wire isn't located at the 7 O'clock position the plug wires are not arranged correctly as well.
The TM 9-8014 illustration of the plug wire arrangement was incorrect and was corrected by a change to the manual.
If the cam was 180 out then the engine would not run at all.