A little update. I dropped the new cylinder head off at the machine shop and they showed me the video of the pressure test. The leak is by one of the lower pushrod holes. There is seepage through what looks like the casting grains if that makes any sense. There are no visible cracks.
70 Challenger 1960 Town Wagon P Pump 24v cummins project 06 Mega 3500 Drw 2wd 12 Durango R/T 18 Power Wagon 67 A100
