Yes, well, uuummm, thats a good question Don. No idea, an "expert" set it at 6 btdc even tho I told him about the cam, she would hardly even reverse after that, so I told him to reset her back to what it was, he refused, said I would stuff up my crank and I think he then just upped the idling, got home and we set it ourselves by ear, been like that ever since. We did try and check with the timing light but some twit went and painted about 5 different timing marks in white, got to get rid of them and repaint my spot.