Man, silicone hose or not...that's gonna be some SERIOUS heat soak in that T-stat housing!. That t-stat will probably kick open way before the cooling system is actually up to the proper temp. Well in defense of the ram-horn design, most people I see using a custom made version remove the factory fans and add push fans in front of the radiator. About 30 minutes of R&D woulda made them a lot of money. I gaurantee that the piping was originally made for some honda mani and they just fitted it to a 420A flange without checking a damn thing.