They should be ready to ship by next Monday. They are tested to confirm they spin freely without any leak prior installation so your engine MUST be cranked few turns without any engine start to ensure there will be enough oil lubrication into turbo cores prior idle. No core exchange is required but i may consider to refound $100. if they are good (no damage on impeller blades and no crack on exhaust housing) and you will sent them to me on the same Garrett boxes used to send you the rebuilted turbos. Thanks for reading