Leveling out a 4Runner limited was super easy using this kit I found on eBay. Not affiliated with seller. Always make sure to get a proper alignment after any suspension modifications! www.ebay.com/itm/401364785159...
You can install a complete new suspension package from someplace like Dobinsons, icon, old man emu, etc… you would need all new coil springs and struts/shocks. I personally like a slightly firmer ride which the Dobinsons gave us on a previous 4Runner. It helped eliminate the nose dive when braking and felt more stable overall.