This project has caught my interest. Will an M119 drop right in? You might need custom mounts. What about the weight difference? I wonder if you will need a custom drive shaft? What about all of the elcectronics?
These guys can make you up a nice custom radiator. All aluminum no plastic!
http://www.wizardcooling.com/catalog/customer/home.php
This would be one cool car. It sounds like a fun project!