Coldwater, MI: There has been a demand in the market for a better riding, better performing suspension system for the 2001-2010 Chevy/GMC HD trucks. With many of these trucks still on the road, BDS Suspension has developed and is excited to announce the release of new upgrade options for the torsion bar IFS converting over to premium quality FOX 2.5 factory series DSC coilovers. Available in 4.5" and 6.5" lift heights, these new coilover conversion systems are based on BDS's tried and true high clearance IFS systems, now integrating FOX's coilover technology gathered from extensive testing. Similar to the widely popular coilover conversion systems offered for the late model 2011-2018 HD's, these new coilover conversion systems bring next level performance, capability, and ride quality to the 2001-2010 Chevy/GMC HD platform with room for up to 37" tires. Get more out of your HD with these new coilover conversion systems from BDS and FOX.

Product Description

4.5"/6.5" Coilover Conversion Systems
for Chevy/GMC HD Trucks/SUVs

Vehicle Fitment

2001-2010 Chevy Silverado 1500HD/2500HD/3500HD 2/4WD
2001-2010 Chevy Suburban 2500HD 2/4WD
2001-2010 GMC Sierra 1500HD/2500HD/3500HD 2/4WD

2001-2010 GMC Denali 2500/3500HD 2/4WD
2001-2010 GMC Yukon XL 2500HD 2/4WD

Kit Info

#738FDSC - (6.5" C/O System, rear block) - $4795.33 msrp
#739FDSC - (6.5" C/O System, rear leaf) - $5479.92 msrp
#740FDSC - (4.5" C/O System, rear block) - $4778.40 msrp

BDS Coilover System Features

  • High clearance crossmembers increase clearance
  • FOX 2.5 DSC coilovers for improved performance
  • Performance UCAs for increased travel
  • Increased protection w/ front+diff skid plates
  • Eliminates rough riding torsion bars
  • Allows for up to 35-37" tires (37s for 6.5" kit only)

Available Accessories

Single Steering Stabilizer Kit (#85411)
Dual Steering Stabilizer Kit (#55363/85423)
Carrier Bearing Drop Kit (#121612)
Fixed Traction Bar Kit (#121618)
Recoil Traction Bar Kit (#123409/121407)

Factory Protection Plus
  • 5-year, 100,000 mile drivetrain warranty
  • BDS’s exclusive No Fine Print Warranty


BDS 4.5" Coilover Conversion System
BDS 6.5" Coilover Conversion System
BDS 6.5" Coilover Conversion System
BDS 6.5" Coilover Conversion System

4.5"/6.5" Coilover Conversion Systems - Ever since the launch of BDS Suspension's coilover conversion systems for late model (2011+) Chevy/GMC HD trucks there has been a huge demand in the aftermarket for similar options for the earlier 2001-2010 HD trucks and SUVs. BDS answers that call with new 4.5" and 6.5" high clearance coilover conversion systems engineered for next level performance. These kits build on the BDS high clearance system technology offering increased ground clearance and improved suspension, steering and driveline geometry and pairs it with the race proven pedigree of FOX 2.5 factory series coilovers to soak up the harshest terrain and on-road comfort.

At the heart of these systems you'll find the FOX 2.5 factory series coilover with remote DSC reservoir. These coilovers feature a smooth bore and honed seamless alloy body, 7/8" hardened stainless steel shaft, FOX coil springs, black anodized machined 6061-T6 billet aluminum mounts and FOX's DSC (dual speed compression) adjustment technology. The DSC adjustment allows for easy adjustment of the vehicle’s suspension compression damping to dial in the ideal ride performance to soak up the bumps, both large and small. The DSC has 12 adjustment points for the high speed compression as well as 10 adjustment points for the low speed compression allowing you to make large or small changes to further improve your performance on any terrain. Adjustments can be made by simply twisting the "blue" high speed and "gold" low speed compression knobs located on the end of the remote reservoir of the FOX 2.5 coilovers. No tools or shop adjustments needed, allowing you to tune the suspension out on the trail. The coilovers come fully assembled, preset for either 4.5" or 6.5" of lift for optimal wheel travel. To mount the coilovers BDS supplies a bolt-on bracket that installs on the frame in the shock mount location. A weld-in support gusset is used to reinforce the upper mount, however still allows the kit to be completely reversible if the owner ever chooses to revert back to the torsion bar style suspension and upgrade the suspension on another truck.

In addition to replacing the factory torsion bars, the upper control arms (UCA) are upgraded to improved strength, travel, and accommodate the new coilovers. The uppers are new performance series upper control arms designed specifically for this system to integrate with the 2.5 coilovers. The arms are fabricated from large 1.5" OD x .120-wall tubing, fully welded and gusseted for the highest quality, strength and durability. The arms utilize premium Moog brand ball joints and factory style rubber bushings for smooth, quiet operation and superior durability when compared to arms with uni-balls, poly bushings or heims. The ball joint cups are repositioned for optimal performance allowing for improved suspension travel. These upper control arms are finished in a durable black powdercoat and include a billet aluminum ball joint dust cap. The control arms come fully assembled for easy install right out of the box. The factory cast steel lower control arms are retained with the addition of a robust lower coilover mounting bracket.

Along with the coilover conversion, these 4.5"/6.5" coilover systems includes a pair of one-piece laser cut high clearance crossmembers, CNC machined ductile iron steering knuckles to correct steering angles, heavy duty front skid plate and differential skid plate to increase protection, multipoint differential relocation brackets to secure differential and correct CV axle angles, CV spacers, and longer sway bar links. In the rear, these kits are designed to level the stance to the front. BDS offers a 3" rear block kit for the 4.5" systems while the 6.5" systems are offered with your choice of 5" rear block kit or replacement GlideRide leaf springs. The leaf springs have additional arch built into the 5-leaf pack and integrates an overload leaf into the pack to assist with hauling heavy loads. All kits include black e-coated u-bolts along with FOX 2.0 performance series IFP shocks to round out the package ready to offer impressive performance wherever your the adventures lead you. The 4.5" system are designed for fitment of 35" tires while the 6.5" kit allows fitment of 35-37" tires.

If you're looking to get more out of your 2001-2010 Chevy/GMC HD truck or SUV look to BDS Suspension and the new 4.5"/6.5" Coilover Conversion Systems. Head to the BDS website for more info and stop by your local BDS distributor to take your HD to the next level!

© BDS Suspension, 491 W. Garfield Ave. Coldwater, MI 49036
(517) 279-2135 | |

25 Comments on “4.5″ & 6.5″ Coilover Conversion Systems | 2001-2010 Chevy/GMC 2500HD | NPA #313
  • Craig phillipson says:

    Hi I’m from Australia and have a 2003 chev Avalanche, I’ve been looking for a lift kit for it here but no one does them in Australia.
    I’ have seen your 4 1/2 and 6 inch coil over kits that I’m very interested in. Just wondering if you import to Australia and whether the kit would work after the truck being converted from left-hand drive to right hand drive to comply with Australian standard .
    Cheers Craig

    • Carter @ BDS Suspension says:

      Hi Craig,
      All of our kits are spec’d for LHD and have not been tested/confirmed compatible for RHD use so I can’t give you an answer there. Is your ’03 Avalanche a 1500 or a 2500HD model? If its a 2500 (8-lug wheels) these 4.5″/6.5″ coilover conversion kits listed above fit the Avalanche 2500. If its a 1500 model (6-lug wheels) we don’t offer coilover options for it, but we do have 4.5″ and 6.5″ high clearance IFS lift systems available. You can find more info on our LHD kits through our website,

      Currently we don’t have any distributors set up in Australia and don’t offer international shipping on retail orders. Your options to purchase a kit would be (A) go through a current BDS dealer willing to ship internationally ( or (B) work with a freight forwarder that can provide you with a US ship-to location to deliver the order.

  • Jonathan says:

    Hi Carter,
    Very interested in this kit for my ‘04 Sierra 2500HD. Right now I have my t-bars cranked to clear 285’s. Had it done since I bought my truck brand new. The ride quality absolutely sucks because of that. I notice the 6.5” lift can fit 37’s. Will I need to crank the t-bars w/ the lift to clear 37’s? I’d like to bring the ride quality back but w/ 37’s

    • Carter @ BDS Suspension says:

      Hi Jonathan,
      Thanks for the interest in BDS Suspension. This 6.5″ coilover conversion system is a great option for improved ride quality, on/off-road performance and additional tire clearance. On your question about “needing to crank the torsion bars to fit 37s”, this particular kit eliminates the torsion bars altogether and the “spring” in the suspension would be the FOX 2.5 factory series DSC coilovers. The coilovers come preset for 6.5″ of lift on trucks equipped with the diesel engine, but do have a threaded body that allows for preload adjustment to adjust final ride height. That said officially we don’t recommend going taller than 7″ of lift as the rest of the suspension components weren’t designed to correct suspension/steering/driveline geometry. On your question about “clearing 37s” we list our recommended wheel/tire specs for fitting 37s, while other sizes can be used, wider wheels/smaller backspacing specs outside of our recommendations may require trimming or other mods for clearance

  • Mike says:

    Hi BDS!
    I recently purchased a 2018 Chevy Colorado ZR2, and I was hoping to get a lift. I know the issue lies in the dssv shocks that come stock with the ZR2. However, I heard a rumor that you may be working on something to integrate those shocks? Is this true? If so that would be badass and do you know when it would be available?

    • Carter @ BDS Suspension says:

      Hey Mike,
      Thanks for reaching out and your interest in BDS Suspension. The rumors are true, we are have some kits in the working for Colorado ZR2, however as a company policy we can’t get into kit specifics, pricepoint, or expected release date. As kits hit the shelves ready to ship we’ll send out announcements and officially begin promoting. Keep an eye out on our website and social media sites for upcoming announcements.

  • daniel mullins says:

    I need a 6″ suspension lift kit for a 2002 chevy silverado 1500hd 2wd can y’all help me out with that let me kno asap.

  • Jonathan says:

    Carter, in regards to rear suspension. I know you offer blocks or leafs. Does one provide a better ride quality?

    • Carter @ BDS Suspension says:

      Hey Jonathan, both rear options (lift blocks or replacement springs) are will offer good on/off-road ride quality. That said there are benefits to each option. The lift blocks are less expensive, but are more susceptible to axle wrap during hard acceleration. With the replacement leaf springs we build more arch into the spring to eliminate the need to use a lift block as well as include an overload leaf to help with additional load capacity.

  • John D. says:

    Hi Carter, are those upper coilover mounts available to purchase separately? I believe they are parts #0397 & 0398 from box 121654. I have a 10” lift on my truck and want to convert to coilovers.


    • Carter @ BDS Suspension says:

      Hey John,
      Short answer, yes we do offer the coilover upgrade components separately. You can find more info on it at
      More info on the box kit breakdown can be found in the instruction sheets at
      Box Kit #121654 has the frame and LCA mounting brackets and hardware, we don’t list it online, you would have to call our sales team or head to your local BDS dealer to order.

      The kits are designed to be used with FOX 2.5 RR Coilovers, which we offer in 4.5″ and 6.5″ preset lift heights, while they have some preload adjustment, the concern would be limited droop travel as well as potential clearance concerns being we haven’t tested it with other kits outside of our kit options. For more info you can contact our sales/tech support team at (517) 279-2135 or

  • lloyd calicott says:

    Hey guys,

    I have a 2009 2500hd duramax 4×4. I tow a 40ft grand design bumper pull and a 22ft v-nose. The 40ft is about 13k and the 22ft is about 9k. Will this system give me the comfort and capability I am looking for with out sacrificing my ride when not towing? I am also running load lift 5000 air bags which have been amazing.

    • Carter @ BDS Suspension says:

      Hi Lloyd, thanks for reaching out. We’re in a similar situation bumper pulling our 24ft and 30ft enclosed show trailers around the country with a 6.5″ C/O System equipped 2015 HD Duramax on 38″ tires with the AirLift bags in the back as well. The main question here is what’s your trucks current setup, is it lifted or stock height? If the truck is already lifted than the tow capacity with this coilover upgrade kit will be uneffected, just a smoother ride up front. If your truck is stock height now and you’re looking for a complete lift system the taller center of gravity and larger mass of the wheels and tires you’d be adding will have some effect on the towing capability regardless of what the lift installed. Being you already have the AirLift bags installed you’ll want to install the rear block kit rather than the full spring kit being our springs have more arch and would effect the lower mounting point on your airbags. If you’d like you can reach out to our tech support team for more on the topic (517) 279-2135 or contact your local BDS distributor to discuss the options,

  • Johnny says:

    Hello wanted to know is you guys had A convert kit of torsion bars to coils for a 2001 1500hd 4×4 and it is 8 lug

    • Carter @ BDS Suspension says:

      Hey Johnny, this kit is compatible with your 2001 GM 1500HD truck and will bolt on without any issues.

  • KEVIN says:


    • Carter @ BDS Suspension says:

      Hey Kevin,
      We do offer an performance UCA kit for the ’01-10 Chevy 2500HD 2WD/4WD trucks, #121252. We don’t offer a spindle only lift kit for 2WD models. Our HD lift kits are primarily designed for 4WD applications which require the crossmembers and differential relocation.

  • Kelly says:

    Fat bons garage here in Utah just put a 6.5 coil over on my 2005 Chevrolet duramax 2500HD LS. They cannot get the truck to align rite so Im waiting on them to figure it out? Ne suggestions on what it could be?

    • Carter @ BDS Suspension says:

      Hey Kelly, I’d assume Fat Bob’s is in contact with our tech support dept, they’re better equipped to offer assist/diagnose than I am from the marketing side here on the BDS blog. Tech support can be reached at or (517) 279-2135

  • Nathan Feissel says:

    Would I be able to run kryptonite upper control arms and tie rods with the bds 6.5 coilover kit on my 2001 duramax

    • Carter @ BDS Suspension says:

      While we haven’t tested that particular UCA/tie rod setup with our kit, as long as those parts are designed as factory replacements they should work just fine

  • Lou Valdivia says:

    Hi BDS,
    I have an 03 gmc 2500 HD that desperately needs a 4.5 lift. I’ve been eye balling your set up and was wondering if your coil overs can fit through my Kryptonite upper control arms?

    • Carter @ BDS Suspension says:

      Hey Lou, that’s not a scenario we would be testing out to confirm clearance/compatibility with someone elses UCAs being we designed this to be a complete coilover conversion.


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