SHAFT LENGTH ..not what your thinking

Simple question about driveshaft length. Im gonna be putting in a AOD behind the 302 and wondering with a 10.0 inch tailshaft on the tranny what length driveshaft am I looking at can I us a regular stock shaft. Or do I have to get it shortened or one made. IVe been thinking about a aluminum driveshaft does anyone know of a place in the San Francisco Bay area that can make one.
Comments and help is appreciated