I bought two of those. One for cabin heat and one for carb heat. They are fine for cabin heat, cause that is what they are made for, but have to be completely re-engineered to be used for carb heat. The hose flanges can be purchased from Spruce or Wicks and the box can be made from bent aluminum and pop riveted, but the flapper valve may be a bit more difficult.
Brian, if the price is right, I will bet there is a good market for boxes and muffs, because they are way over priced. See N64KR at http://KRBuilder.org - Then click on the pics See you in Mt. Vernon - 2006 - KR Gathering There is a time for building and a time for FLYING and the time for building is OVER. Daniel R. Heath - Lexington, SC Has anyone got a drawings, plans of a home made cabin heat and Carb heat they may have made. A/Spruce have them for $100 US phl shipping.