LT1 chevelle

My Car Is Throwing Code P0372, Timing Reference High Resolution Signal A Too Few Pulses. I Need Some Suggestions On What To Do To Fix It. I Had The Harmonic Balancer Off The Other Day, I Am Going To Take It Off And Make Sure It Is On Correctly. I Recently Changed The Opti, Cap And Rotor, Coil Any Other Suggestions Are Welcomed. I Do Not Believe That It Is A Wiring Issue, I Have A New Street And Performance Harness.