Yes you can put Windows 8 on it... the 13 is screen size.
The space would be a squish because you need a swap file and spare room to stop fragmentation… I suspect the wifi and camera will hit driver issues as well but you can work around the wifi by using a v-network bridge and 8 has a lot more support from outside Microsoft when it comes to apps.
Back it up first!
p.s. Does it have to be 8 i.e. 10 would work as well as a dual and doesn't need a license?