[olddog]

I'm kinda new around here. I have been following your tale of woe. Some thoughts that may be of help to you. There is a company that advertises a pressure sensitive paper (very thick). The paper changes colors when it is compressed at different pressures. I get the advertisement at work a lot. Sorry I cannot tell you the name off the top of my head, but if your interested I will find it.

A bad thread on a bolt or in the block could cause a bolt to bottom out before touching the head. This would cause a gasket to leak even though the bolts are torqued and nothing is warped. It wouldn't hurt to run a tap down all the threads in the block if you pull it back appart. Check the head bolts very close. Even new bolts can have a ding. Find a nut and make sure they spin freely all the way down the bolts.

Before pulling it appart, dry out the cylinder. Then pull the rocker off the intake and exhaust valve, to keep them closed, and leave the plug out. Keep radiator full of water. Let it sit over night and see if the cylinder fills up again. If it does then the water had to come in after the valves (likely head gasket). If you suspect water leaked through a valve pull the intake and see if the port is dry or full of water.

I know shops that pressure tested the water jackets on some 4 popper heads. Maybe you can find one that can verify that there is not a water leak in that head.

That leaves the block deck, and cylinder wall. You may want to see if there is a shop that has torque plates that they bolt on during the boring process that would let you borrow them. Torque them down with a gasket. You will be able to see into the cylinder. Pressure the radiator and check the cylinder for a leak (piston down). I think you would have to pull both heads to seal up the block with the torque plates, but you may be able to seal up the manifold jackets of the other head and leave it on. Not sure about that.