or you could talk to silverfox over at click click racinghe knows AODs real well, the alternative is to use a aode or 4r70w from a v6 stang with a manual valvebody.
the speedo gear doesnt take much to change its reall y easy. you can order one from the dealer, they arnt that expensive i think its like 3 bucks or something like that.. there is a chart out there let me see if i can find it.