0 TDC / Top dead center.
1986 should be carburatored and it is not required. That would only apply to a fuel injected engine.
Look at this: http://autorepair.about.com/library/firing_orders/bl-fo-5830.htm
That requires an OBD2 engine scanner to set the timing. You can NO longer use a timing light.
6 to 8 degrees BTDC---- Before Top Dead Center.
Timing chain
Chevy 302the 5.0 302 is a ford engine do you mean the 305?
This should use a crank sensor- so the timing is controlled by the computer and no adjustment provisions are there.
separate a timing connector on the firewall in engine bay which allows you to time the engine,then adjust the distributor.The connector is on the drivers side below the cowl and when separated the engine will run differently.
advance your timing 6 degrees due to this ethanol crap fuel we run now
The base ignition timing for a 1974 Chevy 454 engine is between 8 and 12 degrees below top dead center. A timing light is needed to accurate set ignition timing.
Rpm needs to be set at 800 - 900 .. that is factory setting.
what is the ignition timing for a 1988 Chevy 454 engine