2008 Cummins 6" Long Arm BDS Lift Kit (BDS638H)
Take your Cummins to the next level of stance and control of a 4-Link Long-arm suspension while sending it off to the moon with a full 6" of an increased ride height! This suspension system features 6" progressive Pro-Ride Coil Springs and solid steel upper long arms and thick tubular lower long control arms. The long control arm reduces caster change through wheel travel creating a more controlled feeling in the steering wheel both on and off-road.
Tire & Wheel Combinations:
- 37" x 12.50" w/ 17 x 9 and 5"
Notes:
- Measure rear axle tube before placing order. Some models with dual overloads will require p/n 406
- Rear lift options will not fit dually applications.
- If driveline vibration occurs, order 122801 or 122802 transfer case index kit.
- Exhaust modification will be required for dual rear shock kit 12200
- Will not fit Cab and Chassis models
Installation:
- Click Here For Installation Instructions
- Difficulty: 3 (where 1 = easiest and 5 = complicated)
Part Number: BDS638H

6" Front Coil Springs
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6" Long Arm Box Kit
This Box Kit includes the following products:
- Pitman Arm
- Track Bar Bracket
- 2 Sway Bar Links
- Driver & Passenger Side Sway Bar Mounts
- Bolt Pack
- 2 Bump Stop Brackets
- 2 Urethane Bump Stops
- Driver & Passenger Side Brakeline Adaptor
- 2 Steering Stops - Weld On
- 2 Sway Bar Link U-Bracket
- 2 5/8” ID Hourglass Bushing
- 2 3/4” ID Wide Hourglass Bushings
- 2 .625 x .109 x 1.375 Sleeves
- 2 .750 x .090 x 1.575 Sleeves
- Bolt Pack - Sway Bar Hardware
- Rear Brakeline Bracket
- Front Driveshaft Spacer
- Bolt-Pack - Driveshaft
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Control Arm Box Kit
This Box Kit includes the following products:
- 4 UCA Sleeves .750 x .095 x 2.33
- 2 LCA Sleeves 1.00 x .1875 x 2.60
- 2 LCA Sleeves 1.00 x .120 x 3.25
- 8 90 Degree Grease Zerks
- Driver & Passenger Side Upper Control Arm
- 2 Lower Control Arm
- 8 UCA Bushing - 3/4” ID
- 4 LCA Bushing - Axle
- 4 LCA Bushing - Frame
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Control Arm Mounts
This Box Kit includes the following products:
- Driver & Passenger Side Long Arm Bracket
- Bolt Pack
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This system is available with either the standard rear block kit or new BDS Glide-Ride rear leaf springs. Both of these options are available to work with the 2 rear axle diameters. Please measure your rear axle and select the appropriate rear kit for your vehicle.
4" Rear Block Kit - (4" Axle Tube)
This Box Kit includes the following products:
- 2 5" Bump Stop Blocks
- 2 Leaf Pins
- 4 9/16 x 4 x 16-1/4 Round U-Bolts
- 8 9/16 SAE Flat Washers
- 8 9/16 Fine High Nuts
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4" Rear Block Kit - (3.5" Axle Tube)
This Box Kit includes the following products:
- 2 5" Bump Stop Blocks
- 4 9/16 x 3-1/2 x 14-1/2 Round U-bolts
- 8 9/16 SAE Flat Washers
- 8 9/16 Fine High Nuts
- 2 Leaf Pins
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5" Lift Leaf Spring - (3.5" & 4" Axle Tube) (2x)
BDS Glide-Ride leaf springs will reduce axle wrap and create a more controlled and stable feel when towing. The actual leaf spring may not be exactly as shown in the photo. Includes OE-style bushings installed.
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Required if you have selected full Leaf Spring replacements.
Important: Measure your rear axle & select the appropriate kit.

U-Bolts - (3.5"X12.5") (4x)
Select these U-Bolts if you have a 3.5" Axle Diameter.
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U-Bolts - (4"X12.5") (4x)
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