A bit of an update: I threw the crank in the block along with stock pistons at all 4 corners. With a compression height at 1.855", the stock slugs sit around 0.040" in the hole at TDC, which puts the deck height at about 10.205". So (assuming 58cc combustion chambers) the 3.0L flat tops would get me about 10.1:1 static CR depending on the exact installed thickness of 0.020" head gaskets, which seems like a pretty good number for what I'm after.
Stock slugs are not 1.855. They would be 1.835 for 71. Unless they are aftermarket. And at .040 below deck, someone may have been in this engine before. You will need to measure again with new pistons installed.
The pistons that came out of the engine are the stock/original pistons (stamped with p/n- 1231899), and the compression height might be a few thousandths less than 1.855”, but it’s definitely not any less than 1.850”. One other bit of information I did neglect to mention in my update is that I found the invoice from having the machine work done on the heads (15 years ago!) and I did have the block decked 0.010”.
I've gotten a few more measurements, and here's where things stand currently: The deck height of my block is 10.205" and the actual CH of the 496P pistons I'm using is 1.804", so they'll sit roughly 0.091" below deck. The combustion chambers in my heads are 56cc, so using a 0.020" head gasket will net me a 10.37:1 SCR. Throughout the next couple months I plan to get the port work done on the heads and have them flow tested, so hopefully by spring time I'll be able to legitimately select a cam that'll work well for my combo.