Check in with US Car Tool. Chris was the guy telling me about it. They were making a tunnel/crossmember for the T-56 but I'm not sure when it will be available. I bought their GM 200-4R crossmember to put in my Dart. Like you, I eventually want fuel injection, but the trans swap will be first. Will be nice to cruise 60mph @2K rpm with 4.10 gears and still run 10's all day long. The T-56 will be a lot of fun though!