* Specific Engine Code: The engine casting number (located on the block) will identify the precise engine configuration. This is crucial because different versions had different camshafts and therefore different timing requirements.
* Carburetion: While you've specified a four-barrel carburetor, there were variations even within that.
* Emissions Equipment: The presence and type of emissions control devices (e.g., EGR, catalytic converter) also affects the optimal timing.
Instead of trying to guess, here's the proper procedure:
1. Find the Engine Code: Locate the engine casting number. It's usually a series of letters and numbers cast into the block, often near the driver's side front.
2. Consult a Factory Service Manual: A factory service manual for your *specific* 1983 Dodge 318 with the identified engine code is the only reliable source for the correct timing specification. These manuals provide detailed instructions and the exact numbers you need. You can often find these manuals online through various retailers or used book sellers.
3. Use a Timing Light: While you've used a timing light, ensure you're using it correctly. This involves connecting it properly to the #1 spark plug wire, hooking it up to battery power, and making sure you have a clear view of the timing marks on the harmonic balancer. The engine should be at idle speed.
4. Adjust the Distributor: Once you have the correct timing specification from the service manual, loosen the distributor clamp and adjust the distributor's position to align the timing mark with the specified degrees before top dead center (BTDC). Re-tighten the clamp.
Without the engine code, any timing specification I give you would be unreliable and could potentially damage your engine. Getting the service manual is the only way to ensure you set the timing correctly.
