Our 1/2” diameter steel U-bolts (1/2"x 2-3/8"x 7" for stock '65/'66 stepped-down rear) allow you to use 65 lbs. of torque when tightening as opposed to the OE 7/16” U-bolts only withstanding 45 lbs. of torque. This significantly increases the clamping force as they are much stronger than the stock units. Automatic increased length also allows use with 1“ lowering blocks. Unfinished steel set includes four washers and four nuts.