1. He raised his arms above his head.

2. He raised his arms over his head.

(Can we use both over and above? Do they have the same meaning?)

3. The sun's coming up above the mountain.

4. The sun's coming up over the mountain.
(Can we use both over and above? Do they have the same meaning?)

1=2

3 I have never heard #3
I'd think: as opposed to "below" the mountain?
4 is ok