Cam swap without pulling motor

One sign that’s always a red flag for me is…….when the head/deck surfaces have been subjected to some “cookie dusting”
It wouldn’t surprise me if the extent of the cylinder head “rebuilding” consisted of much more than cleaning, valve lapping, new seals.

But that will be revealed after they’re torn down.

Did you locate a casting number under the runners?

As for the tune up……”meh”
Pretty typical of low CR, big cam(low cyl pressure), unleaded fuel.