I removed the entire heating system that also had an A/C evaporator (which was strange since the bus didn't have A/C). I had the heater core tested, then mounted it length wise under the cabinets in the hallway with 2-14" elec radiator fans pushing the heat just straight out into the hallway. I also have a ball valve after a T to shut off the big heater core, but still allow the driver's defroster to work. Right behind the driver's seat is the thermostatically controlled on/off. So when I'm in cold, I simply turn on the ball valve, then adjust the thermostat. It is so powerful, that when it comes on, even without ducting, you count to 10 and can feel the heat up in the driver's seat. I still have the booster pump, but have never had to use it-get plenty of heat without it. Good Luck, TomC
