Does your '83 D150 actually have an O2 sensor? My OE Lean Burn equipped '83 D150 with a slant six did not.
If there is an O2 sensor, check to see if there are wires going into the fuel bowl on the carb. If there is, you will also need a pre emissions controlled carb.
Concerning just disconnecting a couple of sensors. The Lean Burn system controls the engine's ignition advance, so if the Lean Burn was not getting the correct inputs it is not likely that it would function better.
