This project will use a Ford Sierra Front Differential 4×4, 3.92:1 front differential (from a non-Cosworth Sierra 2.0s 4×4). Normally this diff would bolt to the alloy sump with integral drive shaft. However, for this application the diff will be mounted in front of the engine, with a custom drive-shaft assembly.
The drive-shaft assembly will also incorporate a diff strengthening plate between the diff and the bottom cover.
The first stage in creating a front axle assembly started with drawing up the bottom differential cover.
Click here for more info on the Ford Sierra Front Differential