I was able to make some prototypes for my "water jacket" as I am calling it. They are in approximate order of their design and conception from the top left being the earliest, bottom right the latest. I started printing parts using Blu-Print material because it is designed for 'high heat' applications. I thought it might come out clear because the material on the spool is very clear but turns out it becomes very cloudy with the print settings I've been using. I decided to switch to T-Glass for no other reason than I thought it would be neat to see through the part and its glass temp is also well above the measured temperatures I recorded in my testing.

It seems the T-glass has a lot less shrinkage than the Blu-Print, just something to keep in mind. Its not a big deal as the gaps between the material and the heat sink will allow greater thermal expansion to occur and be taken up by the silicone sealant.

Ultimately I might make the part out of Taulman Alloy 910 because it is the strongest material I have on hand and the last thing I want to have happen is for one of the nozzles to snap off during rapid movements and have the system to disgorge all of its water on the build platform. For now however I am quite happy with the fit and appearance of the part so I think I am ready for some testing with water to see how water tight the part is.