MaxTrac 913321 Semi-Round U-Bolts F-250 F-350 8" Lift

Heavy-Duty U-Bolts for 8-Inch Lifted Super Duty Trucks

Complete your rear suspension setup with the MaxTrac 913321 Semi-Round U-Bolt Set, built for compatible 2017–2026 Ford F-250, F-350, and dually 4WD applications using 8-inch lift blocks. These extended 5/8-inch steel U-bolts provide the length needed to secure taller rear block configurations.
Made in the USA and protected with a gold zinc-plated finish, the 913321 set is a solid choice for replacing U-bolts or completing a lifted Super Duty rear suspension.

Key Features

Designed for 8" Lift Blocks

Extended 21.5-inch U-bolts are sized for compatible rear suspension applications using 8-inch lift blocks.

Heavy-Duty 5/8" Diameter

The 0.625-inch diameter steel construction provides substantial clamping hardware for lifted F-250 and F-350 rear axle setups.

Semi-Round Profile

Semi-round construction is designed to match the applicable Super Duty axle and suspension configuration.

Gold Zinc-Plated Finish

Gold zinc plating adds corrosion resistance while providing the distinctive MaxTrac hardware finish.

F-250, F-350 & Dually Applications

Fits compatible 2017–2026 Ford Super Duty 4WD applications, including dually models with the required modification on applicable 2020+ trucks.

What's Included

5/8" semi-round U-bolts
MaxTrac 913321 U-bolt set

Vehicle Fitment

Fits

2017–2026 Ford F-250 Super Duty 4WD
2017–2026 Ford F-350 Super Duty 4WD
2017–2026 Ford F-350 Dually 4WD
Compatible applications using 8" rear lift blocks

Important Notes

U-bolt dimensions listed by MaxTrac are 21.50" x 3.215" x 0.625".
Designed for compatible 8" lift block applications.
2020+ dually models require removal of the top-side overload spring and spacer block.
Gold zinc-plated finish.
MaxTrac does not recommend wheels wider than 9" or wheels with less than 4.5" backspacing. Using wheels outside these specifications may void applicable manufacturer warranties.

Product Specifications

Brand: MaxTrac Suspension
Part Number: 913321
UPC: 706199414498
Kit Type: Lift / Level
Product Type: Semi-Round U-Bolt Set
Application: 8" Lift Blocks
Position: Rear
U-Bolt Length: 21.50"
U-Bolt Width: 3.215"
Diameter: 5/8" (0.625")
Drive Type: 4WD
Material: Steel
Color: Gold
Finish: Gold Zinc Plated
Sold As: Set
Weight: 17 lbs
Dimensions: 36" × 6" × 4"
Country of Origin: USA

Why Choose MaxTrac 913321 U-Bolts?

Large rear lift blocks need appropriately sized hardware, and the MaxTrac 913321 is designed specifically for compatible 8-inch Super Duty lift applications. Its extended semi-round design, 5/8-inch steel construction, and zinc-plated finish make it well suited for lifted F-250, F-350, and dually suspension builds.

Perfect For

8" rear lift block setups
Ford Super Duty suspension builds
F-250 4WD lift applications
F-350 lifted trucks
Dually rear suspension setups
Replacement extended U-bolts