Yes. Those four marks are for the magnetic pickup system Chrysler was using in the 70s and 80s. See thse tubes that are on the timing tabs? Those were for the magnetic pickups that dealerships used on their timing lights and diagnostic machines. Everyone else just uses a timing light.
The top timing tab was the one used on trucks and cars where you could see the tab from the top. THe ower tab is mainly a van thing due to the short nose of the van.
If it isn't immediatly obvious which timing mark on the damper is the one you use to find TDC on the #1 cylinder, then you are going to have to use a piston stop tool to find TDC manually. Part of the problem is the four timing marks, part of the problem is the fact that the timing marks are on the outer ring of the vibration damper that is bonded to the inner ring and the vulcanized rubber that holds the outer ring on can degrade over time and allow the out ring to slip. When the outer ring slips it no longer accurately indicates TDC. The only thing to do then is find TDC manually usuing a piston stop tool. It isn't hard, but you have ot know how to do it right.
(1) remove plug from cylinder 1 (1.5) remove the valve cover over cuylinder 1 and rotate the crank while watching the valves. Rotate the crank until you see the intake valve on piston 1 open and then close. This ensures you are on the compression stroke. (2) install the piston stop tool (3) rotate crank clockwise by hand until piston contacts the piston stop tool. (4) make a line on the damper at the TDC mark on the timing tab (5) rotate the crank counterclockwise until piston contacts piston stop tool (6) mark a line on the damper at the TDC mark on the timing tab. (7) TDC on the crank is halfway between the two marks you made on the damper. Don't be surprised if true TDC does not line up with the mark cast into the damper. Make a new mark at true TDC on your damper. (8) rotate the crank clockwise until the true TDC mark you made on the damper lines up with TDC on the timing tab. Congratulations. Your motor is now at true TDC on the compression stroke of the #1 piston. (9) disconnect vacuum advance hose and plug it (10 ) reinstall the plug in #1, along with the #1 plug wire (11) start engine and use the timing light to set your base timing a specified.
