Detroit Speed Assembled Center Section FN988 Torque Arm 31Spl REM Polished Gear 070881-331DS-R

The Detroit Speed FN988 Torque Arm Differential delivers exceptional performance for 3rd and 4th Gen Camaro and Firebird enthusiasts seeking modern refinement and strength. It combines the quiet efficiency of the Ford 8.8 gear set with a dropout center section and integral torque arm mount, creating the ideal solution for vehicles running a 9”-style housing. By merging the proven durability of the Ford 9” with the smoother, more efficient design of the 8.8, the FN988 offers a high-strength, low-noise differential built for serious performance. Featuring a 31-spline Truetrac differential, 1350-series yoke, and five gear ratio options, it delivers unmatched driveline control, reliability, and durability - engineered, tested, and proven the Detroit Speed way. ENGINEERED FOR STRENGTH Detroit Speed’s FN988 Torque Arm assembly sets the standard for precision and performance in differential design. The integrated torque arm mount eliminates the need for additional brackets common in 9” axle housing swaps, improving the tight packaging constraints in 3rd/4th gen F-Bodies. Each case is cast from high strength nodular iron and machined to exacting tolerances. Forged steel bearing caps further increase strength in high horsepower application. Assembled with a 31 spline True-Trac Differential, Ford Racing gear sets, high quality bearings and heavy-duty 1350 yoke ensures durability under modern power levels, making it ideal for high-horsepower LS and LT builds. TRUSTED BY TOP INDUSTRY PROFESSIONALS Designed with professional builders and advanced enthusiasts in mind, the FN988 is trusted and used by many of the highest quality build shops in the country. The quiet, efficient operation offers a level of refinement consistent with the high quality builds across the country. Its precise geometry, housing alignment, and superior materials make it the perfect foundation for Pro Touring and performance builds requiring exact tolerances and modern driveline control.

• Engineered for Strength – Nodular Iron and Forged Steel bearing caps for high horsepower reliability.
• Quiet, Efficient Operation – transmit more power to the tires while eliminating gear whine.
• REM Treatment – reduced friction and heat, increasing component life.
• Ease of Installation – Dropout center installs into 9” housings and eliminates C-Clip axles.
• Integral Torque Arm Mounting – Refines the packaging and installation of a 9” housing in 3rd/4th Gen Camaro applications.
• 31-Spline Truetrac Differential – Delivers smooth, predictable power distribution and superior traction.
• 1350-Series Yoke – Heavy-duty construction for high-torque durability.
• Built to Detroit Speed Standards – Precision-assembled for performance, reliability, and perfect fit.
• Multiple Gear Ratio Options – 3.08, 3.31, 3.55, 3.73, and 4.10 gear ratios available, refer to part number for specific ratio.

Attributes:

• Brand Name: Detroit Speed - Archived
• GTIN: 00806990235732
• Axle Type: FN988
• Finish: Coated
• Gear Ratio: 3.31
• Grade Type: Performance
• Material: Nodular Iron
• Mounting Hardware Included: No
• Mounting Hole Quantity: 10

Extended Information:

• Country of Origin: US
• Emissions : Emissions Compliance Exempt

Packing Information:

• Quantity of Each: 1
• Package UOM: EA
• Dimension: 20 x 13 x 13 inches
• Weight: 84 POUNDS