BDS 4-Inch Radius Arm Lift Kit — Ram 2500 SKU: BDS1660FPE | Ram 2500 2019–2024 | 4WD | Diesel | 4" Front / 2.5" Rear | FOX 2.5 Performance Elite Series | Coil Spring Front and Rear

A complete 4-inch radius arm suspension lift kit engineered for the 2019–2024 Ram 2500 diesel 4WD — equipped with FOX 2.5 Performance Elite Series shocks. Heavy-duty tubular replacement radius arms mount in the factory location with caster adjustment and OE-style rubber bushings. Diesel-specific progressive rate Pro-Ride coil springs provide the 4-inch front lift. A precision transfer case indexing ring and high-clearance transmission crossmember address driveline geometry at this lift height. The rear uses progressive rate Pro-Ride coil springs for a 2.5-inch rear lift, with a track bar relocation bracket, bump stop extensions, and sway bar links. Supports up to 35-inch tires with 37 x 12.50-inch configurations also referenced in BDS tire/wheel data.

Before ordering: This kit will not fit Ram 2500 models with factory air ride suspension. Diesel 4WD only.

Verified Fitment

Component Specifications

Lift Configuration (this SKU):

HD Radius Arms:

Pro-Ride Coil Springs — Front:

Pro-Ride Coil Springs — Rear:

FOX 2.5 Performance Elite Series Shocks (front and rear):

Recommended Tire and Wheel Configurations (trimming may be required):

What Is and Is NOT Included

Included — Front:

• Diesel-specific progressive rate Pro-Ride coil springs (pair)
• HD tubular radius arms (pair)
• Forged drop pitman arm
• Track bar relocation bracket
• Sway bar relocation hardware
• Brake line brackets
• Transfer case indexing ring
• High-clearance transmission crossmember
• FOX 2.5 Performance Elite Series front shocks

Included — Rear:

• Progressive rate Pro-Ride coil springs (pair)
• Track bar relocation bracket
• Bump stop extensions
• Sway bar links
• FOX 2.5 Performance Elite Series rear shocks

This kit will not fit:

• Ram 2500 with factory air ride suspension
• Gas engine models
• 2WD models

Critical Compatibility

• Air ride: This kit will not fit Ram 2500 models equipped with factory air ride suspension.
• Diesel only: Diesel-specific Pro-Ride coil springs are included. Gas engine Ram 2500 is not supported — see BDS1699FPE for the gas FOX 2.5 variant.
• Coil spring front and rear: Both the front (4-inch) and rear (2.5-inch) use progressive rate Pro-Ride coil springs.
• T-case indexing ring and crossmember included: At 4 inches of front lift, both are required and included.
• FOX 2.5 vs. FOX 2.0: The 2.5 Performance Elite features a 2.5-inch body, external reservoir, 7/8-inch shaft, and a DSC Dual Speed Compression Adjuster — allowing on-the-fly tuning for terrain, load, and speed. The FOX 2.0 variant (BDS1660FS) is the same kit at the 2.0 shock level.
• ADAS recalibration: Required after installation. All recalibration costs are the owner's responsibility.

Installation Notes

Professional installation is strongly recommended. This kit is rated Moderate with an estimated installation time of 8–10 hours. A pitman arm puller is the only specialty tool required.

Verify before beginning:

• Confirm truck does not have factory air ride suspension
• Confirm diesel engine
• ADAS recalibration appointment scheduled

Professional alignment is required after installation. Refer to the current BDS Suspension installation instructions for SKU BDS1660FPE for complete procedures, torque specifications, and component-specific instructions.

The Obsidian Take

The BDS1660FPE is BDS1660FS with the shock upgrade — FOX 2.5 Performance Elite replaces the FOX 2.0. Same 4-inch radius arm front lift, same 2.5-inch coil spring rear lift, same diesel-specific Pro-Ride springs, same platform and fitment. The 2.5 Performance Elite adds an external reservoir to separate shock oil from nitrogen, a larger 7/8-inch shaft, a 2.5-inch body for increased oil capacity, and the DSC Dual Speed Compression Adjuster for terrain- and load-specific tuning. If the build sees varied terrain, load changes, or high-speed off-road use, the DSC adjuster earns its price. If the truck is predominantly street with occasional trail, BDS1660FS at the FOX 2.0 level is the more efficient spend.

This Product Is For You If

• You own a 2019–2024 Ram 2500 diesel 4WD in a verified trim without factory air ride suspension.
• You want a 4-inch radius arm lift with 2.5 inches of rear coil spring lift.
• You want FOX 2.5 Performance Elite shocks with the DSC adjuster and external reservoir for terrain-specific tuning.
• You want up to 35-inch tire clearance (37-inch configurations also referenced in BDS tire/wheel data).
• Your installer has a pitman arm puller — no welding or cutting required.

This Product Is Not For You If

• Your Ram 2500 has factory air ride suspension.
• Your Ram 2500 has a gas engine.
• Your Ram 2500 is 2WD.
• You want FOX 2.0 shocks at a lower price point — see BDS1660FS.
• You need more lift — see BDS1680FS for the 6-inch diesel radius arm kit.

Product Family Reference

Common Questions

What is the difference between BDS1660FPE and BDS1660FS?
The shock option only. BDS1660FPE includes FOX 2.5 Performance Elite Series shocks with an external reservoir, 7/8-inch shaft, and DSC Dual Speed Compression Adjuster. BDS1660FS includes FOX 2.0 Performance Series shocks. All other components, lift heights, fitment, and installation requirements are identical.

What does the DSC adjuster do?
The Dual Speed Compression Adjuster on the FOX 2.5 Performance Elite allows the driver to tune both low-speed and high-speed compression damping independently — adjusting the shock's response for different terrain types, loads, and speeds without removing the shock.

Does this kit fit Ram 2500 trucks with factory air ride?
No. This kit will not fit models equipped with the factory air ride suspension package.

Does this kit fit the gas Ram 2500?
No. Diesel-specific Pro-Ride coil springs are included.

What specialty tools do I need?
A pitman arm puller is the only specialty tool listed. No welding, cutting, or grinding equipment is required.

Does ADAS need to be recalibrated after installation?
Yes. All ADAS sensors require professional recalibration after installation. All recalibration costs are the owner's responsibility.

Manufacturer Data Disclaimer

Fitment, specification, included-component, and installation data for this kit are sourced from BDS Suspension manufacturer documentation and OFAS-verified product data current as of publication. Specifications are subject to change without notice; confirm current documentation for this SKU at the time of purchase.

Required Legal, Warning, Fitment, and Return Notices

Fitment Notice: This kit will not fit Ram 2500 models with factory air ride suspension. Diesel 4WD only.

ADAS Recalibration Warning: This kit alters vehicle ride height and suspension geometry. All advanced driver assistance system (ADAS) sensors require professional recalibration after installation. Schedule recalibration at an authorized dealer or certified ADAS service center. All recalibration costs are the owner's responsibility.

Installation Warning: Professional installation is strongly recommended. A professional wheel alignment is required after installation.

Tire Fitment Notice: BDS references configurations up to 37 x 12.50-inch tires. Trimming may be required. Buyer is responsible for verifying tire and wheel clearance for their specific vehicle and build.

California Proposition 65 Warning: This product can expose you to chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Return Policy: All returns require prior authorization from Obsidian Forged Auto Supply — do not ship any product back without a Return Merchandise Authorization (RMA). To request an RMA, contact OFAS at Support@obsidianforgedautosupply.com or 469-407-7538 (Monday–Friday 9am–5pm CST, Saturday 9am–3pm CST) with your order number, product SKU, return reason, and photos. Return requests must be submitted within 90 days of delivery. To qualify, the product must be new, unused, uninstalled, complete with all hardware and included components, and in original manufacturer packaging. Do not write on, tape to, or place shipping labels directly on the manufacturer's product box. Return shipping is the customer's responsibility in all cases. Non-defective returns may be subject to a 15% restocking fee. No restocking fee applies when OFAS shipped the wrong item or the return is due to a verified defect or approved damage claim. Some products — including special-order, electrical, and installed items — may be non-returnable. Return eligibility is also subject to applicable manufacturer and supplier return requirements. Approved refunds are issued to the original payment method within approximately 10 business days of the warehouse receiving and processing the returned product. For damaged, missing, or incorrect shipments, contact OFAS within 48 hours of delivery, retain all packaging, and do not install the product.