Being able to remove the sliders does have advantages. I'm not sure how a body lift plays into that. Personally, I wouldn't want my sliders too much higher than the bottom of the frame rails irespective of how high high the body sits.

http://www.4x4extremesports.com/MySport/MVC00005.JPG

http://www.4x4extremesports.com/MySport/MVC00006.JPG

But, drilling through the frame always gives me the willies. The best solution if you're going to drill a box frame is to drill through, stick a thick wall tube through the hole and weld it around both ends to the frame. Then run your bolts through that. No matter how close you possition the bolt to the 'edge' eventually, if you actually USE the skids on a regular basis, cracks are going to develope. And, as has been pointed out, if you DON'T do that you'll just start compressing the rail.

From the pro weld on camp:

The mounts are stronger - if done correctly. The legs should be gusseted on the top to the mount plate.

No annoying rattles.:-)

Easier to mount as you only have to deal with one side of the frame.

Doesn't require actually cutting into the frame - less worry about rust over time since its usually impossible to paint inside a box frame.

And, if done correctly, there won't be anything draging below the bottom of the frame rails. Not as big a deal for SWB vehicles since break-over is different.

Edward