Flywheel will not turn during Starting!!!

Pull the spark plugs and accessory belt/s, see if cranks any better? Maybe something trying to sieze?

Changed spark plugs about a week ago and drove it for a week before it broke down. Starter gear was cracked so i replaced the starter. I will try the serpantine belt but any other ideas.

Try to crank without the spark plugs. You don't need the spark plugs to crank. Maybe hydrostatic lock/fluid in the cylinders? My last thought is something mechanical causing the engine to sieze.

One of the cylinders was full of gas. Both valves ov that cylinder open and close when cranked by hand. What could cause gas to be in oil pan?

Could be an injector problem. Also, Check the fuel pressure regulator, vacuum hose. If there is gas in the hose, the regulator is faulty. You need to fix the gas issue, first.

You may have to change oil and filter more than once, to get all the gas out.