A gaseous fuel introducer comprising a first mounting surface shaped and located to couple to a first wall of a charger; a first input, the first input being an air input; a second input, the second input being a gaseous fuel input; and a charge output. The charge output supplies a fuel-containing charge to an input of the charger. The introducer has a first mounting position that defines a first orientation of the second input relative to the charger. The introducer also has a second mounting position that defines a second orientation of the second input relative to the charger that is different than the first orientation.