So for anyone that has seen my other posts, I finally got the 68 running smooth after cleaning out the carburetor with some carb cleaner. It also needed a new starter because I found out the old one was bad after I had autozone test it. Replaced it, fired the car up and it was sweet music. Turned it off to run an errand and when I came back, went to start it up again and nothing. Tried turning the crank with a ratchet and it doesn't budge. How did my motor just seize up out of no where when it was just running smooth? What are my options at this point?