Billet Aluminum Subframe Bushings

One item that is often overlooked by W-Body enthusiasts is the subframe bushings. GM incorporated a rubber style isolator which lightly presses into the aluminum subframe. While this design is excellent at reducing the amount of NVH (noise vibration and harshness) transferred to the cabin, it is far from conducive to a performance oriented build. Also noteworthy is the fact that these cars are approaching or have surpassed the 20 year mark and in many instances the overall condition of the rubber inserts has drastically deteriorated with time.

LS4 King has addressed the shortcomings of the OE style bushings and now offers two different replacement options. You can purchase a direct drop-in billet bushing kit which duplicates the overall height of the OE style inserts as well as a weld-in version which allows the end user to raiser or lower the subframe in proportion to the frame rails. Both products are machined from solid aluminum blanks.

Eliminating the flimsy rubber bushings allows the subframe to be utilized at its full potential as a structural component of the chassis. The reduction in movement at the four mounting points will allow you to put more power to the pavement while also providing improved feedback from the road. Many customers have even reported tighter and more responsive steering as a result of this simple modification. Purchase of the weld-in style bushing kit, or the optional 1/2” spacers for the drop-in variant has the added benefit of increased hood clearance for enthusiasts using taller intake manifolds or thick intercooler cores for the supercharged V6 applications.   

Both billet bushing kits will work with all original equipment W-Body LS4 subframes as well as all V6 cars equipped with an aluminum subframe.

Please note: The weld-in bushing kit will require an experienced professional tig welder familiar with aluminum for proper installation. Vehicle alignment required after installation.