I assembled it by loosely fitting the timing cover, installing dampener, then oil pan, torqueing oil pan, then tightening/torqueing timing cover. Oil pan was straight, while I had it off I welded in an oil baffle and made sure all the flanges were good.
I made a timelapse of most of the engine assembly:
That might have done it. The timing cover should have been tightened first. I'm not really sure it makes a difference, but that is the correct order. Also, I have seen NEW pans have that front rail bent down so it will not compress that front seal. It's certainly worth disassembling to get it right.