A 4/6 on an OBS looks really good. You will most certainly want to notch the frame though. As long as youre fairly careful and dont hit bad roads to fast. I loved mine, and it never had to much trouble with bottoming out. If you ever want to go back up its a bit easier and cheaper than continuing lower (provided you save the stock parts). If you want I can send pics of my truck with both the 2/4 and 4/6 drops on it so you can get some ideas.