I have a 1995 TA that is all stock. I am replacing the factory harmonic balancer with a stock type aftermarket balancer made by Dayco / Powerbond. The factory unit has an arrow that was aligned with the hub mark from the factory. It also has a pin in one of the balancer holes.

The new Dayco / Powerbond unit has the same holes around the outside with no pins. It is part number PB1481N. It is neutral balance according to Dayco / Powerbond.
1) Do I just install the Dayco / Powerbond unit with the arrow aligned with the hub mark without installing any pins (even though the factory unit had one)?
2) Why does the factory unit have the pin? It is to make it neutrally balanced? (if so I assume I don't need to use the factory pin in the new Dayco / Powerbond balancer.

 

Stock LT1 balancer is not keyed. When #1 is at TDC the pointer on hub should be at 12 o'clock to reduce chance of vibration. The front half of LT1 is neutral balanced the rear half is externally balanced.

 

There is no heavy side to a stock LT1 "balancer." It's actually a damper. Because it's internally balanced in the front, the damper can be positioned at any point. For those who want to argue about holes drilled into the damper differing from one damper to the next, those holes are to ensure the damper is neutral balanced, and they are not all created equal.