Under intake manifold plate rust...
 

I got a lt4 intake manifold and the under plate got some little spot of rust on it.

What should i do with it:
-Leave it like this?
or
-Sand it and thats it ?
or
-Sand it and paint it?

Thank you

That part is non-painted steel and will rust if exposed to air and moisture. I'd use a scotch brite pad and knock the rust off it. Make sure to blow the part off when done. Then take a rag and wipe some oil on it. When mounted on the car it won't rust as it will be oil covered as oil splashes in the lifter valley.

I wouldn't paint it. You don't want any paint flaking off in there. Bare steel inside valley is well enough protected by all the oil.