Why it's not a single number:
* Ignition System Type: 1980 Chevrolets used various ignition systems. Points and condenser systems require a mechanical dwell adjustment, usually between 28 and 32 degrees. Electronic ignition systems (like the HEI, common in many 1980 models) don't have a user-adjustable dwell. The dwell is controlled internally and automatically.
* Distributor Variations: Even within the same ignition system type, there could be minor variations in distributor design affecting the optimal dwell.
* Engine Variations: Different engine sizes and configurations (small block, big block) might have slightly different ideal dwell settings, even if using the same ignition system.
To find the correct dwell:
1. Identify your ignition system: Look at your distributor. If it has points and a condenser, you'll need to adjust the dwell. If it's an HEI, you generally don't adjust the dwell.
2. Consult a repair manual: A shop manual specific to your 1980 Chevrolet model and engine is crucial. It will specify the correct dwell range for your specific vehicle. This is the most reliable source.
3. Use a dwell meter: If you have a points-type ignition system and need to adjust the dwell, you'll need a dwell meter to accurately measure it. Adjust the points gap to achieve the correct dwell specified in your repair manual.
In short, without knowing the precise engine and ignition system of your 1980 Chevrolet V8, it's impossible to give you a definitive dwell setting. Always consult your vehicle's repair manual.
