I don't like block lifts, it creates spring wrap that will just cause increased stress on the springs, ujoints, etc., etc. If you do go with one make sure you get a steel set, the aluminum blocks will wear from the torque and loosen in short order. A shackle lift which is easier and just as cheap would be your best option until you can get a better set of springs. It is fairly common for 4Runners to sag due to the extra pounds they carry with the top. Now I have had a truck with blocks before but I bought it that way and I did feel the difference over a rig without. I think they are refering to the block thickness as to the 2.5 or 3.5. You can pick those up at any 4x4 shop, 4 Wheel Parts is in Compton not to far from you on the 91 and Wilmington.
