* Year of manufacture: The specifications changed slightly over the years the 327 was produced (roughly 1955-1969).
* Cam specifications: Different camshafts have different optimal timing requirements. A mild street cam will have different timing than a performance cam.
* Ignition system: The type of ignition system (points, electronic) can influence timing needs.
* Fuel and carburetor/fuel injection: The fuel used and the delivery system will affect combustion characteristics and therefore optimal timing.
You will need to consult a specific repair manual for the exact year and specifications of your particular 327 engine to find the correct timing. The manual will usually specify initial timing (often around 6-10 degrees BTDC but could vary considerably) and potentially how to adjust the timing for best performance, often involving a dwell meter and vacuum advance adjustments.
Attempting to set the timing without the correct manual and tools could damage your engine.
