Dual-Boot Windows 8.1 and macOS Sierra

Hello, so I want to install the macos sierra on my secondary HDD and I have some questions.

I have this:
Intel Core i3-2100
Asus P8H61-M LE
8GB Ram
AMD HD7750 Sapphire OC
1TB Seagate HDD with Windows 8.1 x64 (Legacy install)
320GB WD HDD with 53GB partition for macOS and 250GB for data
16GB kingstone usb 3.0 flash drive with macOS sierra and uefi clover

I just want to know if my data on the 250GB partition will be safe if I will install macOS on the 53GB partition.Also has anything changed...

Dual-Boot Windows 8.1 and macOS Sierra