To break the clutch free put the truck in High Gear (4th), place two wheel chocks about one foot in front and behind the rear wheels so when it breaks free it doesn't roll away, release the parking brake and rock the truck by hand back and forth. This method has worked for me in the past.
The 10-3/4" Clutch Disc is the shock size for your truck. I don't think there would be any issues using an 11", it will grab a little sooner and be less likely to slip under heavy load.
Any good machine shop should be able to resurface your existing flywheel.
Mike B
