Im having issues with my motor, once I get to about 2700-2800rpms it starts to pop and misfire. It started doing it for a few seconds then it would run just fine. Now it does it every time. I have hooked it up to a scanner and it does not activate any codes. The rpms will jump +/- 500rpms on its own. I have also noticed that the cam retard angle will go from 46 to 66 to 81 when it starts to act up. The entire motor has been rebuilt, heads rebuilt, everything on it is new except the distributor itself, crank sensor, map sensor and TP sensor. Another thing I notice is that in order to set the cam retard angle I need to rotate the distributor quite a bit and it no we’re near parallel to the intake housing. If I skip a tooth and go the other way the spark plug wire hits the intake housing and won’t let me set the correct cam retard angle. Anyone with the flat top distributor mind looking to see how parallel it is set on your motor and letting me know. Thanks in advance.