Engine won't cool off!!

I had a 66 Sport Fury with the old Poly 318. It had over 100K miles and ran hot. A Chrysler mechanic I knew rebuilt the engine and it still ran hot, 190 to 230 and sometimes boiled. I went through thermostats, bigger radiator, clutch fan, you name it and no luck. It usually ran hot but did not boil although got close. After moving to Missouri, it only got worse. I took it to a shop in Lee's Summit I won't name on the forum. They had it for months and told me they could find no problem. I started it up and water gushed out like a garden hose. They told me it was condensation from sitting so long. Right. I got it home and a buddy and I decided to adjust the valves. Ha! Green radiator fluid came squirting up through the oil galleys in the heads. We clamped it down and made calls. We were told, it could be a blown head gasket and or a cracked head/block. I had too much money in this engine to have it all done again so I decided to junk it. I sold the Weind intake, the custom cam, carb, custom throttle linkage and all that. We found radiator fluid under the intake, on top of the pistons, and when we dropped the oil pan, green radiator fluid sitting on top of the oil. What I'm getting at is I was able to drive this car running hot, borderline boil over, took it one garage after another, spent a fair amount of money with these garages who could not identify the problem (it could have been one that started small and grew bigger over time), spent a lot of money on radiators, tranny coolers, you name it, and still lost the battle. I would begin a systematic look at each part of the cooling system ruling out each problem as I went. Of course start with the thermostat, hoses, and all that because those are a cheap fix and move out from there including a block flush. A head gasket is not the end of the world but you don't want to end up cracking heads and blocks. I hope this helps a little.