I screwed up piston #4. Once I got my leak-down flange bolted to the deck I was able to confirm I still had a leak into the block with the piston at TDC. I then put the piston at BDC and lined the joint between the bore and piston top with a strip of butyl caulk. This time... no leak at all.
I took a closer look at the piston. The portion of the piston crown that is closest to the intake/exhaust side of the block was not coming all the way to the top of the deck. It appears my rope pushed that side down, probably pinching the compression rings so they cannot follow the bore anymore.
I have contacted a friend and left a message asking if he has a used +.030" piston for a 1500. If he does, I'm going for the cheap "fix" and address only what failed. If he doesn't have a piston for me my son and I will pull what's left of an engine and tear it down so the machinist can tell us what size new pistons we'll need.
I'll post pictures before tearing it down but the damage is very subtle and wouldn't likely be noticed if you didn't know what you were looking for.
Depressed in Durham,
Doug L.
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