You can probably get it to work but by the time you buy a used one and and rebuild it you are close to or even more than the cost of a new T-56 Magnum. Plus the 6060 from a caddy has the shifter WAYYY back, the Challenger has a weird Mercedes style yoke.

I spent a lot of time researching it look at Quicktime for the bell. In the end buying a Keisler or American Powertrain Kit was the best option for me.
Scott