For sale is a used pair of Timbren TOR4R SES helper bump stops. These replace your factory rear axle bumps and act as cushy helper springs when you load up. Comes with steel spacers and large washers to set the height where you want it.
The directions say these can be used on 3rd gen and 2nd gen 4Runners.
These work really well and are very smooth. It's an easy solution for increasing the amount of load you can comfortably carry.
These suckers go for >$200 new on Amazon. Asking $100 or best offer, located in SFO and willing to ship.
Original box and directions included.