I apologize if this is old news, but I needed to replace the U-shaped heater hose that goes between the fitting on the top of the plenum and the thermostat housing. I couldn't find this in a preformed hose, and I was concerned that a straight hose would kink in this tight-turn application. With the help of my local auto-parts store, I got a Gates Hose No. 18400, which apparently is used on a few Japanese cars (Honda Prelude, I think, is one). Anyway, it is pretty close, as you can see, and I think will work well in this application.