1973 Dodge Dart Swinger seized slant six

There's 73 Dart that I want but there are some problems with it. The person who is selling is being very reasonable with the price, so if I see that it can be fixed, I plan to purchase.
The engine is seized because of overheating. Is attempting to un seize it do-able or is a new motor in order?

This is how the seller explained what happened:
it has a slant six, a heater hose got disconnected and
all the coolant drained out and the car overheated
while i was driving it, i bought a new heater control
valve and heater hoses and it has a newer water pump
and thermostat and alternator. Before the overheated
occurred, the car had problems shifted gears, but i
put more transmission fluid in it and it shifted fine
after that, the tranny may actually be fine, i just
wrote that as worse case scenerio because i wasnt able
to drive long enough after before the overheating took
place.


Any advice/suggestions? The body is in great shape and I'm all about taking it on as a project, I'm not too concerned about the tranny issue, I just want to know if being able to un seize it is a reality.

If it overheated and is seized to many parts are damaged to be fixed without a rebuild.

Lucas Transmission stop slip is awesome if your transmission just slips a little. As far as the engine it is most likely gonna need a rebuild if it seized while you were driving. You could try putting transmission fluid down the spark plug holes on the pistons and letting it set overnight. Then you can try and turn the engine with a crow bar but that usually is something done when a car is seized from sitting for a very long time so no guarantees. Good luck.