When a body lift is performed on your vehicle, many things need extending.
To make your body lift work, there are a number of components that will need extending to ensure the connection between chassis and engine is maintained. The most critical extension is the steering extension, which has to be carefully designed and compliant (i.e. no zinc plating or welding).
Without the right body lift extension, your steering shaft could snap.
Scary, but true. Of course it's imperative in terms of safety for you and your family to ensure that full spline engagement is integral... because in some cases steering shafts have snapped due to fatigue and too much flexing so close to the end of the shaft. An extension will fix this!
And don't forget the other components that need extending...
...air inlets often need extending when you perform a body lift, and in those circumstances the extension should be carried out to ensure there is no cutting or modifying required so that you know the vehicle can be brought back to factory settings if required.
Electrical wiring, brake lines, and fuel filler hoses are all other parts that may need extensions.