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Do you know if your Uncle bought it new or Used?
Clicking on this link below, you can Order the NCRS Dealer Delivery Report that shows what Dealer your car was Originally Shipped to new, likely who sold it too but not always if Dealer Traded etc.
https://www.chevymuscledocs.com/
Also, whatever Engine(s) you have in or out of the car, note Castings also #’s Stamped into the Block Deck Surface that protrudes beyond the Front of the Pass. Side Head. Original GM Stampings should indicate what engine built for new also whether Original to your car or not.
If you want to dig deeper, there’s Transmission also Rear Axle Tube Stampings you can check too.
Welcome aboard Jeff!
~ Pete
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