Installed these as new front shocks on a 2005 4Runner. This kit was all stock at the time and had no screws. For 4Runner/GX470 you need M10x1.25 fine thread bolt. Most hardware circuits only provide m10x1.5 but are too crude. As for durability, who knows. I heard that polyamide breaks under heavy impact compared to rubber. I just have to keep an eye on them when I hit rough terrain. However, my car is primarily a street car and I wanted them to prevent impact damage since I use spacers on the 1/4" top plate.