AccuAir VU4 4-Corner Valve Manifold (NPT) Interior replacing the worn factory plastic

replacing the worn factory plastic with a piece that won't fade or crack

Once you've lowered your C3500's rear end

Rather than piecing together individual components

6" rear drop using their proven

Stone Fab hand-builds this kit for serious OBS builders who want real handling improvement without committing to a complete suspension overhaul

AccuAir VU4 4-Corner Valve Manifold (NPT) Interior replacing the worn factory plasticThe valve manifold is the heart of any 4 corner air management setup, and the VU4 is built to handle it cleanly. One manifold controls inflation and deflation independently at all four corners, so you get true 4 corner control instead of just front rear. Every port is 1 4" NPT, which keeps plumbing straightforward whether you're running a simple setup or adding a digital controller later. If you're building out a real air ride system on your OBS