I will not comment about the customer service or honesty of the previous posters new engine but there is an explanation. As a repair facility, be it a dealer or an independent, when you order an engine from the manufacturer, in this case GM, you do not know if you are getting a factory rebuilt or a brand new. You will usually get a new engine only if there was an accidental over run at the engine facility for that particular year vehicle. Numerous times we had multiple warranty and/or customer pay engine replacements going in the shop. Two engine crates for identical vehicles could come in on the same delivery truck and one would be new and the other would be a reman. They are both by law still considered "new" engines.
Randy