Typically we recommend a monotube gas shock for a lifted vehicle. Lifted trucks usually come with bigger wheels and tires, which count as ‘unsprung weight’ and require better damping ability from the shock. A monotube gas shock may transfer more road harshness to the vehicle and driver, but the main purpose of a shock is to keep the vehicle in control and to keep traction. You can go with a softer shock, something like a twin-tube foam cell shock, or hydro only shock, which may ride softer on the highway and over bumps and potholes, but that comes at a sacrifice of control and handling, along with less lifespan of the shock.