Df 300ap lower unit

[Q8SUZUKI]

Hi all, this is my first post on this forum. Hope i could contribute and also at the same get some feedback too.
I was wondering what the scratches are on the following pics below. I dont know whether it has to do with the installation of engine, cavitation issues, or just its a normal thing.

[boats.net]

Hard to tell from pictures but it does look like it could be cavitation burns.

[Q8SUZUKI]

Hard to tell from pictures but it does look like it could be cavitation burns.

Thank you for having the time to reply.

[Harper]

Are you referring to the dark spots on the lower unit? Cavitation burns only happen on a prop as far as I know. The boat itself isn't fast enough through the water to cause a burn.