Now that you have seemingly sorted out your problem, let me offer some additional advice. Now would be a good time to double check the cam phasing as well as tdc. Use a dial indicator on the top of the position and confirm that you have tdc on the compression stroke, i.e., that the cam opening and closing events are correct when the piston is at tdc. cam phasing on the six is critical because of he way the combustion chamber is laid out and how close the intake is to the piston. I once had new gears that were mismarked. Installed them, thought all was well until every intake valve hit the top of every piston and bent all of them. cheap insurance. Just a thought.
