Sorry, late getting back. Checked resistance on position sensor with in specs. It's a 350 done by Street and Performance with 90 Corvette parts and sensors. Map just changed, O2 just changed, timing set when ECM tested, is perfect per computer expert. Even changed out the computer. No different Don't know cam, headers are Sanderson shorty.
Since Street and Performance are no longer in business can't get info from them. Even the expert on these systems can't figure it out. Car runs great other wise.