Hooker makes headers for you application.
BTW, all Clifford intake are not water heated.
Another option is to use Tom Langdons cast iron exhaust manifolds, really nice & would not leak as headers are known for. Two cents.
I thought I seen a water heated Clifford???
With the water heated type manifold ,you can just route your water heater hoses in & out , not really complicated.
You could also clamp or weld a round piece of steel tubing to a header tube connect a piece of flex tubing to that piece of steel tubing you attached to your header pipe & run the other end to your air cleaner,,, if you need the heat?
MBHD