I have a timing gun with advance on it, and I have no idea how the hell to use it. I just want to set the timing on my Z, and I don't know how to properly use the gun, or what to set the timing to. Now I feel stupid for asking.

 

Mine is about 30 years old but the two small leads go to your battery +/-, The large heavy duty one clamps on your #1 spark plug wire. You set your timing with the vacuum advance disconnected and plugged, it should be 5' btdc for 70-72 and 7' btdc on 73-74 cars. Clean and mark your timing marks on the crank damper with white chalk. Looking from the front of the engine from right to left the first mark is 5' atdc the next is 0, then 5, 10, 15, 20 btcd. Check instructions for your Pertronic to see if there is something else you need to do.

 

Then, with your new marks on the crank damper, and pointer, start the car and let it warm up. Set it to the idle speed. The dial on the timing light can then be adjusted to your timing, for example 7 degrees. If the car was previously running at 7 degrees, with the timing light set at 7 degrees (advance) your new marks on the damper and pointer should line up so it looks like it is firing on top dead center, with no advance.

With these lights, if accurate, you could dial in your advance and set it on TDC marks. Also, some cars in the past really didn't give you much in the way of timing marks more than 12 - 20 degrees. With your timing light, you could dial in a high advance setting such as 33 - 37 degrees advance, and run the motor at 5 - 6,000 rpms, and see how close in relationship you are to TDC.

Play around with it, they are fun!

Speed

Enjoy the Ride!