you could make a plate that fits between the manifold and heads, run your NO2 and fuel lines under the manifold. this way you can retain the sleeper status.

it's easy to do, just get a new set of gaskets and trace them out onto some 1/2" or 3/4" phenolic plates. fun project

this will also insulate the heat from the heads and manifolds, I know some shop already makes phenolic spacers for this motor, but I forget thier name, maybe you can contact them for a thicker set, just drill em out to fit your fogger nozzle