Well I got the 235 back together and started it. Initially, it ran well. I drove it for about 5 miles until it warmed up. Once water temp came up and the pressure built up, I started smoking like a steam locomotive again.
Well, this time it's not the head. Water is definitely getting into the combustion somehow. I don't know if it's a hairline crack that I can't see that only sprays when my water pressure is up to 16 psi (yes, modern radiator), or if it's getting into the oil and the watery oil is getting past the rings. One way or another, I think I've eliminated every possibility but the block.
And you know what? An increase to 9.25:1 made absolutely NO difference that I could feel in the seat of the pants. Still a weak, stupid boat anchor of an engine.
I admire those who endeavor to keep these beautiful trucks original, but if I'm going to stay with a stovebolt engine, it's gonna need to be somewhere around or near 300 cubic inches, and possibly even with forced induction.
Trying to get a 3/4 ton down the road on a little over 100 horsepower is horse dookey.