I went with the bolt-on method when I installed my sliders thinking that they would be easier to move later if necessary. I sleeved the bottom bolts & used self-threading bolts on the uppers to avoid compressing the frame. The problem is; now that I have my 2" body lift & I want to raise the sliders, I don't see a way to bolt the sliders any higher on the frame. There's no extra space above the location of the existing brackets, and even if there was, it would leave all the holes from the previous mounting position that would need to be welded up again.

I wheeled with the body lift installed but the sliders in their original positions & managed to bend them upwards somewhat since they don't have the body pinch weld to bear against as they were originally designed to.

I've decided that the best option in my case is to have the sliders cut from the mounting brackets & re-welded 2" higher on the brackets, keeping the brackets in the same position on the frame. So, I would have been in virtually the same situation if I had just had them welded onto the frame in the first place.