I always thought my block was painred, but after removing the heads I see it wasn't. There really isn't much of the block exposed. My bell housing is orange also. Next time you under the truck look behind the exhaust manifolds for signs of paint.
The serial number is located on the drivers side of the block. The spark plug cover needs to be removed to see the flat spot where the number is stamped right between the 2nd and 3rd spark plug on that side.
The fender skirts look neat, but your tires may be to wide for them to fit without rubbing.
Your truck could have come with wood or aluminium ladders as speced by the fire company that ordered your truck. My build sheet said I had aluminium.