John, I don't think it is mandatory to have the intake as big as the output hose. If the intake hose is the smaller of the two, it will be the limiting factor in reaching the potential of the pump. Sure the pump will run longer(using gas) and/or more time required. Have to weigh cost of that versus cost of hoses. Personally, I would equip it to run the size the pump is rated at, and get it done.
