The front spring and shock from the 2000-06 Tundra TRD can be used to lift the front of the 4Runner. The sought after coils from the Tundra are coded Yellow/Yellow and Yellow/Blue. These springs are a progressive rate coil which means that they start out soft and get stiffer as they compress. this gives the 4Runner and soft ride while still providing good handling both on and off road. These springs generally yield about 2.5" of lift. there are companies selling the Tundra spring with a Bilstein adjustable shock which can be adjusted to get more lift.