Revert 1.9 to 1.8

Hello people of the Internet! i would like to know if its possible to set the resource pack creator back to 1.8.
If it is possible, please tell me how. because when i drag a 1.8 resource pack to the 1.9 editor, i loose some
of the textures. please help!

There aren’t too many changes between 1.8 and 1.9.
Can you point some of the textures that you are losing?

mainly the diamond armor and tools. and some of the wood planks