UMI Performance Competition Upper and Lower A-arm Kit, Coilover Only
UMI Performance Competition Upper and Lower A-arm Kit, Coilover Only
UMI Performance Competition Upper and Lower A-arm Kit, Coilover Only

UMI Performance Competition Upper and Lower A-arm Kit, Coilover Only

Regular price $1,279.99


Tremendous front grip and a host of features can be yours with UMI’s 305756-3 kit. This a-arm kit enables 10 degrees caster while maintaining standard track width and wheelbase. The lower shock mount is removable to allow spring/shock changes at the track. The tall lower ball joint optimizes roll center, camber gain, center of gravity and lowers ride height by ½”. Delrin bushings help the lower a-arm to travel smoothly for bind-free operation. The new lower a-arm works in conjunction with our popular 3056-3 adjustable upper arm which features minimal shim adjustability, 1” taller-than-stock ball joints and super smooth rod ends. Also included on the lower a-arm is a double shear sway bar mounting system which accepts UMI sway bars and many other manufacturers stock location aftermarket units. An aluminum steering stop is adjustable and limits steering lock to prevent tire and wheel damage. Available in UMI red or black powder coat. 100% designed, manufactured and raced with pride in the USA. Battle tested on the iconic UMI Green Machine.

Performance note: UMI recommends adding the P/N 3060 bump steer kit for optimal performance.


    • Performance a-arm kit is a direct bolt-in for 1978-1988 GM G-body.
    • Adjustable upper a-arm uses rod ends for easy alignment.
    • Total of 10 degrees caster potential while maintaining spindle pin location.
    • Upper ball joint moved rearward to add 5-6 degrees caster potential.
    • Lower ball joint relocated forward to increase caster 4-5 degrees which improves steering feel and straight line stability.
    • Rod ends feature superior friction reduction for quick response.
    • UMI built Delrin bushings improve steering response and reduce deflection.
    • Taller upper ball joints to improve camber gain, optimize roll center and improve traction during cornering.
    • Upper and lower a-arms built from USA Made DOM steel tubing.
    • Removable double shear mount to allow spring/shock replacement without removing spindle.
    • Mount spacing suitable for Afco, Viking, Ridetech and many other aftermarket manufacturers shock/spring combos.
    • Adjustable steering stop.
    • Double shear swivel sway bar mounts and hardware work with UMI P/N 3035 and most other factory eyelet style sway bars.
    • Designed, tested, manufactured and raced in Philipsburg, PA-USA.

Installation Notes: The 3057-1 is a versatile competition a-arm that can be used with the following springs and shocks:

1. Hybrid coilover kits A224-XXXR and A204-XXXR can be used with no modifications required to the car. The top of the spring fits in the original G-body spring locator in the upper frame. A204 poly bushing coilover kits require bearing kit P/N SSB10T-APK. A224 bearing mounted coilover kits require 2 of sleeve P/N 9556-103. UMI can supply this style shock as ready to install as well. Hybrid coilover spring rates are available up to 650lb.

2. Coilover kits 3058-650 or 3058-850 can be used with trimming to the upper spring locator. Trimming can be accomplished with a torch or slicing wheel. Once trimmed, the benefit of this style hybrid is the fact that there are a vast number of spring lengths and rates available.

3. Coming soon will be a full racing coilover which requires major construction in the upper spring pocket area.

4. Ridtech and other similar coilover setups will work properly. Please contact us for discussion.

5. The 305756 kit cannot be used with standard size coil springs and stock mount shocks.


UMI Performance Competition Upper and Lower A-arm Kit, Coilover Only