I still need to do mine, last trip turned my oil milky. Thought it was a seal, but all the diffs were milky. I would do this ASAP if you plan on going anything deeper than 1.5". If you look at the rear axle you can follow it up, it's rather low.
Rear Axle- route up to gas tank filler nozzle,
Front Axle- Route up through engine bay with RC air filter over tip to avoid dirt ingestion.
Hey wildsmith I would love to see your truck in person next time I'm in England I'm gonna look for you! Did you run the lines direct from the diff etc or attach to the factory ones just for extension? What tubing did you use
Let us know when you're over and we'll see if that can be arranged For the rear diff I replaced the OEM breather outlet on the axle casing with a push fit pipe connector and ran plastic pipe from there to the engine bay. For the front diff I cheated and took the valve off the end of the OEM pipe and pushed my plastic pipe into that. Similar story for the auto box and transfer breathers, pulled them off the dip stick and connected them to my plastic pipe to run to the manifold. I'll take some pictures tomorrow and post them.