I have a 1966 Custlass Supreme that has had an engine swap for a Gold Painted Rocket 350. If I am not mistaken this means that the engine was from a 68-70 and is an L34? Please correct me if I'm wrong. In either case, the current transmission is a 2 speed. I'm not sure what kind of tranny it is, but I'm wondering what kind of tranny I can replace it with. I want to install a 3 or 4 speed tranny, and I'm wondering what will fit, what will mate with the olds SB, and what modifications I will have to make to get it to fit. Any help is muchly appreciated