These new U-bolts are what you need to install a 10 bolt rear using a spring plate on top of the spring. Works on M1009 CUCV rear, K5 Blazer and many other C/K truck applications. There are four u-bolts and hardware in this kit. All the U-bolts are 5/8" dia x 3" x 8" long and include nuts and washers. This listing does not include the spring plates. See the GM 2.5" U-bolt plates here: GM U-bolt Plates, pair (2.5" springs)