Generally speaking, As you know, the 58-59 are dual headlight and 55.2-57 do not, so the hood and fenders won't work. If you are wondering about a certain part, look on a vendors web site and see what years they say it fits. (Sheet metal as well as other Parts). That will be 98.2% accurate. As said, most parts are the same. There were some style/mechanical/electrical updates and things were mounted in different places. You can take the old part with you, sometimes, to a sale or swap meet to compare. To get a specific answer about a part here, you have to ask a specific question like you did on the doors. Your truck is a specific body style of trucks which are approximately the "same", called Task Force, 1955.2-1959. The .2 means "second series", there is a 1955.1 truck (first series) which is part of the previous era/style/design. Welcome to the Stovebolt!
