Before deciding on the type of lift that best suits your needs and budget, you must differentiate between shocks and springs, and dispel the misconception that a mere shock lift will raise the height of your truck. A spring replacement is what actually lifts your truck; a shock lift is a spring lift that raises the entire vehicle, including the body, frame and drive-train components above the wheels. A spacer, or body, lift merely uses blocks to raise the body above the frame while leaving the engine, transmission and driveline bits in the same place. It is important to consider multiple facets of the lifting process when choosing between a spring and spacer lift for your truck or Jeep.
A spring lift requires new shocks, springs and other suspension assemblies that have a higher materials cost than the blocks used for a spacer lift. The installation process of a spring lift also requires more labor hours and more experienced labor for proper installation, while a spacer lift is less labor intensive, lowering the installation cost of a spacer lift.
A spring lift inherently raises the entire truck above the wheels, allowing for increased approach, departure and drive-over angles; this makes it a choice for those looking for increased off-road performance. A spacer lift raises the body of the truck above the frame, which does not increase the approach, departure or drive-over angles of your ride; this makes the spacer lift a choice for those merely wanting the visual appeal of a lifted truck and bigger tires.
A spring lift increases the suspension travel of your truck since it actually achieves the goal of lifting your truck by adding functional suspension travel beneath your ride. Spring lifts give your truck the ability to absorb larger impacts while simultaneously increasing suspension articulation. A spacer lift does not increase functional suspension travel of articulation, and does not offer off-road handling advantages for your truck. However, a spacer lift also retains the factory suspension of your truck, making it handle the same on the road; this ensures you do not have the excessive suspension bob or body lean that can plague trucks with spring lifts.
Trucks with spring lifts have a higher center of gravity since the increased suspension increases the height of the body, frame, engine and transmission. A spacer lift raises the body above the chassis, leaving the original vehicle's center of gravity mostly intact. This is true only when comparing the two styles of lifts to each other, though, and you must be aware that both type of lifts do increase the likelihood of a rollover since they both raise the center of gravity.
Liftability and Aesthetic
Spacer lifts generally top out at 3 inches in total lift, limiting the amount of lift and size of tires you can achieve when using this style of lift. Suspension lifts can go up to 2 feet in overall truck height, depending on your desires. A truck with a suspension lift also tends to look and drive more professionally since the whole body is raised above the axles and the truck's height corresponds to the suspension travel. A truck with a spacer lift sits above the chassis, increasing the amount of visible chassis below the frame, which detracts from the visual appeal.