I'm looking to lift my '99 4runner 3 inches pretty soon and am not sure which route to go. Spring spacer kits seem to be a lot cheaper than coilover kits but I don't know if that's because they're a lot worse than coil overs. Any thoughts?

 

All spacers do is compress your suspension, which in turn raises your rig. It's going to make your rig ride rougher than stock, and less travel. It's not the best for wheeling either, mostly for show.

Aftermarket coilovers are similar to stock coilovers, but are built slightly taller than stock, and most have the ability to be adjusted for height. This allows for a smoother ride, sometimes better than stock, and more travel. Obviously they are more pricey than spacers.

Both will let you run larger tires, which is normally the goal for lifts. It really depends what you use your 4runner for. If your a heavy wheeler, I'd go with the coilovers. If you want it to look good at the mall, get spacers. Myself, I started with a spacer kit, then as I began using my 4runner for more challenging trails I switched over to Toytec coilovers.