Making this took me a morning. It adapts a V12 to a Chevy manual transmission bell housing. A drill press and a way to cut aluminum are the only required tools. Oh and a piece of cardboard to transfer the holes location. The post 1977 Jaguar bell housing uses the same locating pins location as the Chevy bell housing does. So no need to worry about the critical alignment. How thick a plate you start with is determined by which transmission is used. For street use I recommend buying