Well one of the things we seen and think? is one part of a small issue is the Core piece itself. We think they made other cores as we see a little egg shape in the carb port/s but not in all the ports. And the 4cyl intake is what also gave me/we a better clue as to what may have happened in the 6cyl, and with having both poured at the same time we think???? It for surely is that extra time was not taken in the curing process of the cores and may have been laying on their side and this is what could have caused the egg shape???? But pretty much it comes down to quality control.
I will more than likely do carb surface this weekend So I will get a better look to see if we have the same issue on any of those ports.