Put thermostat in backwards?

only fit 1 way.

What else stops flow but thermostat or water pump? That's all it can be right?

No, that's not all it can be... it could be corrosion, dirt, or even rust clogging up and limiting coolant flow somewhere in the block, the radiator, the heater core, even stuck in the thermostat.... Or even dirt in the fins on the radiator or something preventing air flow there. Or an air bubble in the coolant system somewhere if you didn't get it burped out.

id def say stroke... im picking mine up this weekend and i couldnt be happier!!!

How do I get air out/chk it w/out further damage if it's not shot? Is there a thread somewhere?

to get an air bubble out, you fill your radiator all the way the run your engine with the cap off until its at operating tem (thermostat opens) then fill the rest of the way and cap off.

also check the radiator. mine was caked with mud and i overheated like crazy all the time.