OK, time for a quick update. Measured the oil pressure before doing anything with the oil pump. Looks like the pressure climbs to 35 psi and stays there. Sounds like a good pressure, sounds like the oil pump relief valve is functioning. For giggles, I hooked up a compression gauge to measure cylinder compression. After a few cycles, there was none. Zero. Zip. Put my trusty leakdown tester on, and it showed no leakage. But wait? What's that noise coming from the dipstick tube? Air? But why does the leakdown tester say AOK? Hmmmm. Tear the unit apart. Head gaskets seem OK. Pull the pistons out, remove the compression rings, measure the end gaps. Spec for this with a used block is max .030. I'm measuring up to .106. Well well. Why didn't I look at this when I was rebuilding the engine? Because at the time, and even now, the leakdown tester says no leakage, anyplace. Plus, the engine was running OK until a rod went south. Remember the business about burning a LOT of oil, did as leakdown test, was AOK, decided the oil was coming in via an intake valve guide. So we bought all the stuff to remedy that, and maybe all along the smoke was due to really really worn rings, and the leakdown tester lied to me. I am really torqued because I wasted a pile of bucks and who knows how many hours doing work that may not have been necessary. Checked the bore and piston dimensions and they are OK, so today we bought new rings and of course a couple of head gasket kits. Another couple of hundred. Stay tuned for the next chapter. And meanwhile, any idea about what's going on with the leakdown tester? At one point I remember slowly turning the crank beyond TDC with the tester attached, and sure enough, about when the exhaust valve should be opening the tester shows a lot of leakage. So, I figured the tester is OK. Way wrong about that.