Glad you found the problem, screw in plugs are the way to go.
My buddy had a similar issue with his BBC that he built, might have been the same problem plug leaking or something who knows it's gone now.
But anyways, he had all new lunati H beams, Eagle forged crank, new pistons, pressure was low after warm up, around 15/20 idle, didnt last long 2 passes later it spun a couple rod bearings and snapped 2 of them H beam rods like they were tooth picks. :shock:
I tried to check your video out, didnt work for me.
Cp