ok so one of my buddies asked me to build him a set of ladder bars for his f-250. i know what they are. but what exacly are they for. and i know they bolt to the bottom of the frame, does the other end bolt to the axle?!?!

just trying to get some more info on them b4 i build them

 

They reduce axle hop, at the price of limited axle articulation. One end hooks to the frame, the other the axle tube.

I'm sure there's tons of info in the interwebs to help you along.