5th gen springs front springs... on the 5100's will fit and work. that is what I run on the front of my rig. They are about the same as the 99 talls so expect 1" or little more over stock.
Mine are set to second from top (pretty sure. its been a while) C clip, I have Tundra 5100's. The ride pretty good not harsh in my opinion. Its no Kings but good ride.