That kit is actually designed for the late model truck which use the bronze bushing. For our AD trucks you could retrofit the bushings if you wanted to but when I did mine, I didn't bother with the bushing. I just used the new pin which is conveniently oversized from original which will compensate for wear. You will need to drill out the old hinge plates to accept the oversize pins. I can't remember the drill size but you should measure for a snug fit. It is best to use a drill press with the hinges accurately aligned in a vise to ensure precise alignment. The new pins are also longer than original so you might want to grind off the length some.
There is a an article on another site
http://www.classictruckshop.com/door_hinge.asp where they used the bushings.
-Ed
