Matt, I'm kinda stumped on your 3qts a week... I wouldn't think that PCV would pass that much in a week. But as you stated, 210# in all 3 cylinders, rebuilt head and new rings. I have to assume the rings were fitted and installed properly being a fresh .030 over?
Funny story, My wife bought a van many years ago, I took it back to the mechanic found on the door sticker for some service and he kinda freaked out when I pulled up. After I started talking with him he pulls out a 6" stack of service records for the thing(no wonder he freaked eh ! Lol), the last one being where the previous owner had noticed low oil... and refilled it, it goes low again, refilled again... then calls the mechanic as they hear the engine knocking at a light nearby. They pull it into the garage and it's low on oil again. No leaks, no oil smoke. The Engine was toast. When they started to disassemble it they pulled off the valve covers and they were full of oil. All of the oil passages going back to the oil pan were completely closed off with sludge. Before this they never serviced the engine all of the service was to the inside electrical, brakes, driveshaft, rearend and transmission. This was during a period of 3 years and he figured they never changed the oil or filter just added oil. So we reaped the benefit of a new factory engine with darn near a new van from a dealer as they got it on a trade-in.
Not saying this is what's wrong, but seems kind of unusual with it being a fresh rebuld and all.
Good Luck,
RPG0