First,
You need to remove the firewall brackets and firewall. Once those parts are out of the way it will be a breeze to remove the engine.
Second,
I bend a small piece of tin to fit under the pan ear, above the frame rail. Spread a little grease on the top of the frame rail, and with the piece of tin between the ear and frame you will find that the back of the engine will slide forward easily AND not leave a lot of scratches in the top of the frame rail.