UMI Performance · New
UMI Performance 65-66 GM B-Body Adjustable Upper Control/Trailing Arm
MPN 3657-R · Store SKU umi3657-R
Supplier stock checked 11/7/2026, 8:06:45 AM UTC. Adding a part does not reserve it.
Request a return within 30 calendar days after delivery. New parts must be unopened and unused.
Shipping & returns ↗This policy does not limit rights required by law.Free standard shipping on eligible parts orders of $100 or more. Oversized and freight items excluded. Fitment, taxes, availability and final totals are confirmed before payment.
Product details
UMI Performance offers an on-car adjustable control arm for the rear of the GM B-Body vehicle. This control arm is a direct replacement for the factory arms and helps minimize wheel hop and improve cornering. It allows for easy pinion angle adjustments without the need to remove it from the vehicle. The control arm features grease-able bushings, TIG welded construction, and a 4140 heat treated CrMo adjuster. This item is sold individually, so please verify how many you need for your vehicle. It is compatible with both 3-link and 4-link rear suspension set-ups. UMI’s on-car adjustable rear control arm for GM B-Body replaces factory arms to cut wheel hop and sharpen cornering. Features greaseable bushings, TIG-welded strength, and a 4140 Chromoly adjuster. Fits 3-link or 4-link setups. UMI adjustable B-Body control arm cuts wheel hop & allows pinion tuning.
Manufacturer fitment & guides
Check 3657-R against the manufacturer’s application information below.
Part-specific notes
- California Proposition 65: Y
