I would not drill holes in the frame to mount them. I used to run Smittybilt nerfbars years ago but I had them welded onto the frame instead. It only took the local welder a few minutes and I didn't have to worry about any mounting hardware coming loose. And don't think of welded nerfbars as permanent, I later took mine off with just a little grinding of the welds. Now that the welds have been ground off, the frame, since I never drilled holes in it, is as strong as it was before.