I personally do not know if there are makings to identify the swap.
But, a GM dealership can tell you when they run your VIN number. That is, as long as the head was replaced by GM under warranty. If the person did the head outside of GM, I don't know that there would be record of that.
Most (well mine) will give you a carfax check out your paperwork and see if your did, if the head was replaced under warranty it would be in there, other than that visually inspect the head bolts most of time you can see marks on the bolt head where it was removed and reinstalled
I prefer a comma rather than a peiod, not correct punctuation but never had to use one working on my truck, even if most of the bolts are hard to see the timing cover plastic piece is up front and easy to see
Glad i could make you laugh, but if you can figure out how to get the engine head off without taking off the plastic timing cover id be interested. One of us is incorrect, im talking about a easy way to tell if the head has been changed