First up most builders assume an engine will be installed and started right away. Assembly lube only goes so far in protecting bare steel surfaces from rust. Cylinder walls can flash rust overnight. If it was stored for months without the spark plugs in place it would be worse.

I understand feeling wronged after spending a lot of money on a rebuild. If you feel you have a good case we (Kansas) do have an Attorney General with an active Consumer Protection Division. I would be in contact with them & file a complaint.

Edit: I emailed this thread to United Engine. They should have the opportunity to respond and try to work things out with the OP if they desire. I hope it's worked out to a mutually agreeable conclusion.

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