Advice for Cluster configuration

Hello guys, I need your advice
I have next cluster http://prntscr.com/bilh2s
As you can see two nodes have a 32TB hard disk. I want to relocate 80% of data to this nodes and 20% to other 4 nodes. How can I make it?
It's elasticsearch 1.7.5 on board
8 shards with 1 replica.

Friends, nobody can help me?

You should be able to allocate a majority of whole indices to the nodes with more disk space using shard allocation awareness. You can designate the nodes with smaller amount of disk space to belong to one zone and the two more powerful node to a different zone. You should then be able specify the zone indices should be located in and get the distribution you want.

I will read about it, thanks!

as i understand right, this feature only for ES 2.0+ ?
i have ES 1.7.5

It has been available for quite some time. Here is a link to the 1.7 version of the docs.