That is a forward shifting transfer case which more than likely came off of a 84 - 88 carbed. You need to have the rear case a top shifting transfercase, Marlin sells the conversion kit to make that happen. Here is the link off Marlins site to help with some other ?'s you might have.
http://www.marlincrawler.com/htm/transfercase/crawler_installer/index.htm
I called MC about a week ago to get that kit he does not offer it anymore due to lack of parts. I ended up doing some fab work to convert it from forward shift to top and it works great.
