Brothers C-notch kits are awesome! C-notching is the only way to clear the lowered rear axle for these classic trucks. this C-notch kit is made of 1/4 thick steel and is more than enough support for your trucks frame while giving your truck aproximately 3-inches extra suspension travel. Adding a C-notch is always a good idea to retain original ride quality on any lowered truck. Brothers strongly recommends C-notching any truck with a 4-inch drop or more. C-notching will eliminate axle to frame contact. Kit includes frame plates, bump stocks and hardware. Brothers C-notch kits are awesome! C-notching is the only way to clear the lowered rear axle for these classic trucks. this C-notch kit is made of 1/4 thick steel and is more than enough support for your trucks frame while giving your truck aproximately 3-inches extra suspension travel. Adding a C-notch is always a good idea to retain original ride quality on any lowered truck. Brothers strongly recommends C-notching any truck with a 4-inch drop or more. C-notching will eliminate axle to frame contact. Kit includes frame plates, bump stocks and hardware. Compatible with 1973-1987 Chevrolet/GMC C10/C15 Compatible with 1973-1987 Chevrolet/GMC C10/C15