UMI Performance · New
UMI Performance 64-67 A-Body Adjustable Upper Control Arms- w/ Roto-Joint
MPN 4039-R · Store SKU umi4039-R
Supplier stock checked 11/7/2026, 8:20:45 AM UTC. Adding a part does not reserve it.
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Product details
UMI’s Roto-Joint adjustable rear upper control arms are a bulletproof addition to your street or pro-touring car. UMI’s Roto-Joint upper control arms are suitable for street, strip or corner carving. The premium UMI built spherical joint drastically minimizes suspension deflection for a crisp handling setup, easy pinion angle tuning and less wheel hop. These on car adjustable upper control arms adjust easily while staying bolted to the car and are designed to handle virtually any application. The Roto-Joints combined with UMI’s in house designed and machined CrMo adjuster equal ultimate strength and performance. These heavy duty arms feature ¼” thick CNC laser cut mounting pads and a mix of TIG and MIG welding. These simple bolt in replacements install in 1-2 hours and are designed to work on all rear end housings. Launch harder and turn faster with UMI’s ultimate arms! Installation: Item installs in approximately 1-2 hours using basic hand tools. On car adjustment using UMI designed & manufactured CrMo adjuster 4039 - 1964-1967 A-Body Adjustable Upper Control Arms- w/ Roto-Joint CrMo threaded adapters for improved thread strength Durable and long lasting powder coat finish CNC laser cut ¼” upper mounting pads Made in Philipsburg, PA – USA UMI designed Roto-Joints Features
Manufacturer fitment & guides
Check 4039-R against the manufacturer’s application information below.
Part-specific notes
- California Proposition 65: Y
