I found this add on craigslist and I can't figure out if I should get them to replace my sagging rears or not. I emailed him and asked him what he meant and he said:
"yes still have the springs. they are out of a 3rd gen toyota rears...i take the center leafs out and put tacomas in. myself and alot of my friends have run this setup on all of our trucks these where a set that i never used and im going links on my truck so i dont need them. u can run them on either rears or fronts. for front app it moves axle forward 1.5" and the tacoma leafs are from a 04. these up front and chevy 63' springs in the rear are a perfect setup nice and flexy but not super soft. "

So would that fit my 1989 4runner? Does that sound like a good deal? Would it actually do a 4" lift? thanks

 

3rd gen rears are 51" and your springs are 48".

For them you work correctly you would have to move one of the hangers. It might work with just a longer shackle, but your wheel wont be centered in the fender anymore.

Another option would be to make your own bastard pack, using your 48" main leaf, and springs from the add.