Chrysler Repair: Engine analyzer, self explanitory, alligator clip

Question
Hi, I need to connect an old engine analyzer to a 1981 chrysler 318 to get an accurate RPM reading. My friend gave me his old analyzer, and it has 4 connectors on it. The two for the battery are self explanitory, but the other two are a single wire with an alligator clip, and a double wire with a flat plate attached at the end. The plate has a square hole and a groove in it. Do you know how to properly hook this to the motor to get an RPM reading? Is the flat plate an inductive pickup? does the alligator clip go to the coil? Any info would be great.
Thanks

Answer
Hi David,
Unfortunately I haven't seen a device like that, but I would suspect if the groove is large enough for a spark plug wire to slip through that it is meant to be an inductive pickup around the cyl. #1 wire. The aligator clip I would imagine goes to any ground point on the engine. Give that a try and see if you get an appropriate response from the meter movement.
If it is not a sufficiently large groove then I would slide it around one of the spark coil primary wires, and clip the alligator on the post at the coil for the other wire of the coil. If that doesn't produce a reading then reverse the wires to which you attach them.
Roland