Alignment. Your vehicle will likely require an alignment after installation, at additional cost.
Headlamp aim. Check and adjust headlamp aim after installation.
Driver assistance systems. If your truck has camera- or radar-based safety systems, they may need to be re-aimed or recalibrated by a dealer after a ride-height change.
Read the instructions all the way through before starting. Installation by a qualified technician is recommended. Some modifications may not be legal in every state — check your local laws.