JDL: lets keep it simple for now. If you have already put BPblaster in the cylinders go get some diesel fuel and pour about a 6 or 8oz in each cylinder. Thats enough to make sure it covers the tops of the pistons. Let it set for about a week then try to get it to turn from under the truck using a BIG screw driver or pry bar on the flywheel. If the engine is truly stuck it will take some pretty stong effort to break it loose even though its soaked for some time. Once it moves just keep working it back and forth a little at a time until you get it to make a full turn. Once thats accomplished squirt some oil or WD 40 down in it and turn it s few more times. Once its loose you will then need to drain all of it out of the oil pan and put in some new oil before trying to start the truck.
All the strings you found in the clutch area was put there by rats.
