6.2 engine change with spare

I picked up a 2011 super duty with a “bad” engine. But truck came with another used engine to swap. I have no idea what the condition of the spare engine is but it’s not seized at least. I’m thinking I need to change out the timing chain and the exhaust manifold gaskets at a min while the “new” engine is on the stand. It’s been a lot of years since I did a truck engine and I’m not up to speed on the 6.2. I had a 6.4 diesel a few years ago and was a lot of trouble. Any recommendations on parts to change out now?? I don’t want to change the head gaskets unless I need to but it’s tempting without knowing the hours on the engine.