I had to remove the distributor on my 383. Now ive reinstalled it and im trying to time it. Im trying to distinguish the detonation sound. I have it it at 12BTDC right now and it seems to be running good. I advanced it way to much to just hear what the detontation sounded like and all i could here was a metallic ringing. I cant tell if its the open headers or if the timing is off because i can hear crackles. Ive never heard it run without the exhaust before this. I just dont want to damage my engine.