Help with Blockbench, Techne, Mcreator for Minecraft 1.7.10

I have the Mcreator version for Minecraft 1.7.10. I have the Blockbench program and when I want to export a block it does it in .json. That version of Mcreator does not read .json files and when I convert it to Java via internet it compiles badly. I also have the Techne but the hitboxs appear bad, so I wanted to try another program.