We use to unstick old tractors and car engines in the 80's by completley fill the entire engine with kerosene now they fill the engine with diesel fuel pour it right in were you put the oil in on a small block v8 it is around 8 gallons let it sit for a week then drain it turn it over with the spark plugs out then fill it with oil I guarantee it will turn over
I have successfully freed a stuck engine using used diesel engine oil. Filled entire engine, let sit for a couple months. Results may have happened sooner, only couldn't get back to it for that long. Running like a top today.