Quick Hotbar Mod allows you to see a preview of 27 inventory slots while swapping out blocks into the 9 slots you have been given by holding down left CTRL. Use your mouse wheel to toggle inventory rows up or down. As you are doing this, you will get a preview of your inventory slots in game.

Detail and Download here : Quick Hotbar Mod 1.8.9/1.7.10

See also : Minecraft mods 1.8