Fabtech’s round U-bolt kit for rear leaf springs is listed as 5/8-18 x 5.63 x 4.06 with product notes reading 4.06 in. x 5.63 in. x 5/8 in.-18. Designed to fasten and stabilize the springs to the axle, this economical kit is promoted as a simple component to help lift and secure the back of a truck when paired with the rest of a suspension upgrade.
Fabtech Round U-Bolt Kit - 5/8-18 x 5.63 x 4.06