Will DDR3 RAM (1866) work with a motherboard (1600)?

Question

Iron

Available:
1) Mat. board: Gigabyte Z77-DS3H (I don't remember the revision, mine v1.1)
2) CPU: Intel(R) Core(TM) i7-3770 3.40 GHz
3) RAM: KHX1600C9D3/4GX x 2pcs. (1600 MT / s) ( specification )

Instead of the current 2 dies, I want to put the 4th 8 GB HX318C10FB / 8.
There is a line in the specification for the new operative - DDR3-1600 CL9-10-9 @1.5V ( link )
Proc and mother officially support a maximum of 32GB (exactly)

Will there be any problems?
I'm swimming in these issues, please help me navigate ...

Answer 1

Most likely it will work, since the RAM supports a lower frequency mode (1600)

Answer 2

You are trying to push an object 100 cm wide through a door 80 cm wide. Do you think you can do it? :)
Will work at the maximum supported frequency of the motherboard\processor