TDC WAS accurate upon assembly. After I left for DC my son and a friend had to change balancers(from Chevy to Mopar front) so possibly there was an issue there I was not here so not sure. It happened on both gas and E85 with 2 different carbs. I have been overly cautious with the timing but cannot and do not believe it is actually at 48, am assuming that something has happened there. BUt the plugs are showing it wants more timing still. Definitely has me baffled for sure. Oh yeah did it with 2 different E85 carbs as well, so pretty sure it is NOT a carb issue.