Why settle for a rebuilt generator when you can get a brand new one at a very reasonable price? This is a BRAND NEW Bosch 12 Volt generator that we have modified exclusively for Type 3 engines. And because this is a new generator, their is no core charge or core needed. (NOTE*** This is a Type 1 generator that has been modified for use in Type 3, which means you will have to extend your electrical connections because the terminals for the wires are located on the opposite side of the generator - refer to picture. The heat ventilation holes are also located on the pulley side as well but do not affect the cooling of the generator. The original Type 3 generators have a mark on them to line up with the stock bracket for pulley alignment, these New Replacement generators do not have the stock alignment mark so the pulley alignment will need to be done by sight. ALSO, if you are converting your electrical system from 6 volt to 12 volt, a 12 volt type 3 fan shroud must be used to accommodate this 12 volt generator. If you have any questions or concerns, please give us a call) GR16N