Some information about Duff Pack Resource Pack 1.7.4/1.7.2 that you can need before installing

How to install Duff Pack Resource Pack for Minecraft

In order to use HD Resource packs properly (32× and higher) you will need to either patch your MinecraftusingMCPatcher or using OptiFine. Optifine is preferred as it includes all of the features of MCPatcher, and greatlyincreases game speeds and graphics settings. MCPatcher tends to be updated on the same day as Minecraft updates, so use it instead if you are in a hurry. ...

Detail and Download here : Minecraft mods 1.7.5/1.7.2/1.6.4