Nissan Repair: z24 cam sprocket, z24 engine, timing chain

Question
I have a 87 d21 pickup with a z24 engine. While replacing the timing chain and sprockets I noticed 3 positions on the cam sprocket. Which position should I use?

Answer
Lloyd,

The factory Nissan sprocket has one mark.  The aftermarket has three.  I would use the center since that is the middle and the other marks are for advance and retard of the cam.  You may check this by looking at the origin of the single mark on the factory unit and compare it to the aftermarket one, with three marks.  I would say the aftermarket one should be installed straight up, middle mark.  Let me know what you find.  But, my supposition is the middle mark.  When I say to compare look at the drift key location and the middle mark should be at the same orientation as the factory unit.