Most ‘Leveling Kit’ conversations are dominated by the inexpensive spacers that get installed on top of the factory struts/shocks. They are attractive since they’re usually around $100, you don't need a spring compressor to install, and it doesn’t change the ride quality much at all.
But let's not be mistaken; there is no added performance to strut or spring spacers.
Ride Height adjustable shocks like Bilstein 5100, Eibach Pro Truck, and Fox 2.0 IFP Snap Ring shocks not only allow the leveling of the vehicle, or other ride heights in the front, but also give added performance to the vehicle.
When leveling a vehicle, most people put larger wheels and tires on, this usually increases the weight on each corner by 15-30% more than factory - that’s all added stress on the suspension, aka Unsprung Weight.
These 3 brands all achieve similar results, ride heights are a little different per application, but the actual shock behavior is the same regardless of application.
0 is no change
1 is a minor change
2 is a big change
- Handling - 1 - better corner handling, better tow/haul handling
- Bumps - 1 - improves bump compliance and comfort
- Off-Road - 2 - can handle bigger and tougher obstacles at faster speeds
- Handling - 0 - about the same handling, feels improved during tow/haul
- Bumps - 2 - really comfortable on larger bumps and small trail chatter
- Off-Road - 2 - these are designed for off-road use, they shine in the dirt
- Handling - 2 - best corner handling, least body roll, best for tow/haul
- Bumps - 0 - feels firm over bumps and potholes
- Off-Road - 1 - gives more capability off-road, but still quite firm on easy trails