Aftermarket coilovers such as King, Fox, Sway A Way, and the like are adjustable. That means that you can adjust the preload on the spring. So, if you add a bumper and the front end sags, you can twist one end of the spring retainer to compress the spring just enough to compensate for the added weight. This is how you can adjust ride height. If you add preload by compressing the coil just a little, you can raise the vehicle. This can result in a "stiffer" ride, but if you are adding more weight, like a bumper, you shouldn't notice a stiffer ride if you restore the loss in ride height.
Aftermarket coilovers typically provide you with:
1. A stiffer than factory coilspring.
2. Preload adjustable for setting ride height and ride quality.
3. Increased shock diameter, providing longer dampening ability.
4. Specific and changeable valving that controls dampening characteristics.
5. Most units can be rebuilt or serviced.
6. Better performance in prolonged cycling of the suspension. ie desert and prolonged off road excursions.
The other option is replacing your factory springs with "stiffer" after market units such as OME -Old Man Emu. The stiffer springs will appose the added weight of an aftermarket front bumper. The down side to this is you lose all adjust ability. It is a cheaper alternative, so if it suits your needs, this might be your answer.
Do a search for ome and should get 50 pages of info and similarly offited FJ's with a variety of OME combo's to research.
best of luck,
Doc
Aftermarket coilovers typically provide you with:
1. A stiffer than factory coilspring.
2. Preload adjustable for setting ride height and ride quality.
3. Increased shock diameter, providing longer dampening ability.
4. Specific and changeable valving that controls dampening characteristics.
5. Most units can be rebuilt or serviced.
6. Better performance in prolonged cycling of the suspension. ie desert and prolonged off road excursions.
The other option is replacing your factory springs with "stiffer" after market units such as OME -Old Man Emu. The stiffer springs will appose the added weight of an aftermarket front bumper. The down side to this is you lose all adjust ability. It is a cheaper alternative, so if it suits your needs, this might be your answer.
Do a search for ome and should get 50 pages of info and similarly offited FJ's with a variety of OME combo's to research.
best of luck,
Doc