My 483 ci. wedge. Has 6 mild passes, not one full throttle pass on motor. Backed car out to line up and load on trailer, pulled up to ramp. Just as I started to shut it off it developed a rattle in the motor. Not a rod or lifter noise, was like something loose. Got it home and jacked up the front end. Pulled valve covers off and oil pan. Everything looks perfect, not a scratch or ding visible. Rocker arms, push rods, valves, and springs all woking and intact. Took all the plugs out and hit the starter, spun over clean and quiet. So decided to let car down and put up on blocks. Just as it was almost all the way down I heard a clink, best discrip. I can think of. Was going to turn it over by the crank and check each cyl. rockers. Put a long ratchet on it and bingo. It would not move, what ever clinked wedged somewhere and can't turn the motor either direction. Pulled the drive shaft and the trans. turns using the output shaft. And looking at the flex plate and convertor, what I can see. Nothing.
Any help on this would be deeply appreciated. Short of pulling the motor and trans I'm stumped !!!!! Help!!!!!