UMI Performance AB4350-1 Double Adjustable Coilover Lowering Kit with Viking Shocks

The UMI Performance AB4350-1 is a complete bolt-in coilover adjustable spring lowering kit designed for serious street, strip, and corner-carving performance. Built around four Viking double adjustable shocks hand-built in Lakeville, Minnesota, this hybrid front coilover system delivers precise, tunable ride control with no welding and no spring compressor required for installation.

The front coilover system provides a 0–3 inch front drop range, while the rear uses your choice of UMI lowering springs for either a 1-inch or 2-inch rear drop. Lowering the ride height reduces the center of gravity and places the upper A-arm in a more favorable angle for improved handling dynamics. Each Viking shock features 19 independent compression and 19 rebound settings, allowing you to dial in your setup for street cruising, drag strip launches, or aggressive corner carving — simply by turning the adjustment knobs, no tools required.

Front Spring Rate Options:

• 250 lb – 11" tall springs for drag race only; serious weight reduction required
• 350 lb – Small block cruise or drag race; lightening required
• 450 lb – Small block cruise or big block drag race
• 550 lb – Small block handling or all big block applications except drag race

Kit Contents:

• (2) Front coilover shocks, double adjustable
• (2) Rear shocks, double adjustable
• (2) Rear lowering springs — choice of 1" or 2" drop
• Viking Premium Made-in-USA springs, shot-peened and coated for long-term durability

Baseline Shock Settings:

• All-around street: 6C / 8R all corners
• Corner carving: 10C / 12R all corners
• Strip (drag): 6C / 2R front, 6C / 6R rear

Optional Spanner Wrench & Thrust Bearing Kit: A spanner wrench allows front ride height adjustment while the shock remains mounted on the vehicle. The optional thrust bearing kit mounts between the spring and spring seat for smoother, easier height adjustments. While not required for installation, UMI strongly recommends using the thrust bearing kit when making ride height adjustments.

The AB4350-1 is a true bolt-in performance upgrade — no welding, no spring compressor, and no compromise between weekend street driving and track-day performance.