What's the mileage on the engine and what altitude are you at? check out boxwrench.com
The timing for this engine is electronically controlled and not adjustable
The timing on that year engine is computer controlled. It requires an engine scanner to set the timing. YOU CAN NOT USE A TIMING LIGHT.
8 degrees before top dead center.
That requires an engine scanner.
Bring it to a shop and have them adjust the timing with a timing gun I believe its 6*
there was no 350 in the camaros in 83 just 305 and v6
about 16 degrees btdc
cam timing will not change ignition timing i would try 8 or 10 degees advance at idle with the vacuum advance disconnected.