Start the engine and bring it to operating temperature.
Using the timing light, set initial to the setting you would like to test, rotating the distributor CW will advance timing, and CCW will retard timing. 10° BTDC is the stock setting, but you may want to check if 12° BTDC or 14° BTDC will work for more power.
Tighten distributor base bolt and confirm setting did not change.
Reconnect the SPOUT jumper plug into the connector.
Check timing change with the timing light, the reading should be between 20° - 24° BTDC = sign the computer is controlling spark advance.
From the web...for EFI 5.0's