Adopted

That port isn't cracked at all.

That's just a casting line, where the two molds were mated. You can see it in the milling, at the port mating surface. Look at the other port to the right of the pic. Same deal. A crack that big would have gone way deeper and would have shown visible in the port mating surface, where it was milled. That is a normal thing to see.

The 302 heads that I did had some of that, only the other way around and I ended up cleaning the mold line garbage with a carbide. The line doesn't look like it's inhibiting anything. Leave it.

The bottom end does look fresh. Depending on how the parts were cleaned, the varnish is something I've seen before on a few engines. All that matters is the machine work. The varnish won't hurt anything.

You can still see the cam lube on the lifters and some of the parkerizing/ phosphate manganese on the cam itself.

Be sure to run breakin oil on that motor for at least another 1000 miles and be nice to it.

Nice find!