1984 gmc k1500 5.7 350 V8 engine timing and distributor installation

The distributor was not marked when the distributor was pulled out of the engine and my assumption is also that the ignition timing was off to begin with I read the label under the hood and it was saying 4degrees and this engine is a California model I suppose and the Haynes repair manual is stating 4degrees or 6degrees for California model so I have to start over from scratch and put the engine in time with the distributor I do know the ignition rotor spins clock wise and they have the firing order setup for a distributor rotation going backwards.so since I have to set the motor at top dead center and I need to mark on the timing tab plate for 0 and then another mark for my ignition timing witch is 4degrees or 6degrees and I don’t know what to mark on that metal plate with so the timing light can flash on the lines I make to set the ignition timing also correct me if I’m wrong when the distributor rotor is going forward do I turn the distributor cap backwards and vise versa ? when the distributor rotor is going backwards do I turn the distributor cap forward ?