Reddbird350

Hey guys. I have swapped a 95 Firebird 3.4 into my 82 firebird. Due to issues in the past tuning the 7730, I decided to use the factory PCM with a manual transmission to run this engine. I can get the car to run and go into closed loop. No codes register but the timing is off. The motor was from a Fiero swap, has 3000 miles on it and ran great prior to pulling it. (Transmission went out.) The engine shakes at idle. The timing gun shows it is running @ about 14-16 deg bTDC. The balancer was marked for the Fiero. The pcm shows the timing is set at 21 deg. According to the factory Service manual, the only inputs that affect timing is MAP, crank sensor and CTS. All Sensors are new and have been swapped with known good units. I can not determine what is retarding the Timing. The control mdule and coil have been tested and swapped. Using a manual or automatic PCM does not affect the timing. There are no vaacum leaks. (Tested with starting fluid.) Any thoughts would be helpful. Theft deturant bypassed with resistors. Injectors are New 17lb Accel. Fuel Pressure @ 45 idle. Transmission is a TH700R4.