340 Overheat / Radiator Geyser

"Final" update for now. I took it on the highway yesterday. Took 10 minutes to get there, then after about another 10 at 60MPH, same deal. If anything it heat up quicker on this drive than it does when sitting idling. When home and cool I did a very thorough coolant flush. There was a lot of **** inside the end of one of the heater hoses. This thing is very consistent. After 30 minutes the temp gets to just over 3/4, engine stalls, coolant relieves from overflow hose, sound of boiling. I failed to mention that after it gets hot, the metal dash is so hot that you almost can't touch it. For yesterday's drive I had the heat off and as I said I feel like the car heated up quicker. Maybe the heater core is trying to do the radiator's job?
SO...It's pumping water. With the radiator level just below the baffle I can see the water moving. 160 thermostat is new and tested. No obstructions in any of the hoses. Fan turns all the time, it has a shroud, radiator was recored but a looong time ago and the car mostly sat since then. The bubbling of coolant that you saw previously is not happening anymore.
The only temps I am happy with are at the lower hose, which is 150-ish. Everything else is running 180-200 or more.
The next thing I'm gonna try is the combustion leak tool and see if anyone rings-in about the lower hose being an acceptable (?) temp while everything is hot, and maybe see about having the radiator boiled-out, but it's easier to find a nickel bag than it is a radiator shop anymore. Can they test them for flow? In other news, after all of this yesterday I got the news that the as****e squatter still has not vacated the house I'm buying so the closing has been pushed from today to Friday. It was already postponed by 2 weeks. The Sheriff is involved now, but "this I can tell you", after a 2-year search for property, this purchase is never gonna happen, so the clock is likely gonna get turned back another 2 years after Friday. This car may never see a garage again.