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6/18/24 - We are working on website, production, and some in-shop project work. If item(s) you need show "sold-out" on site, please contact us for availability, those parts may be in stock. Thank you.
6/18/24 - We are working on website, production, and some in-shop project work. If item(s) you need show "sold-out" on site, please contact us for availability, those parts may be in stock. Thank you.

GM 4x4 5" Turn-key Hi-Lift Torsion Bar Conversion Kit

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Front Differential/Gearing

This is our turn-key 4x4 conversion kit for 2003-2023 G-series 2500/3500 vans. The design is an IFS (Independent Front Suspension) torsion bar setup similar to GM pickups. This setup is optimized for on and offroad travel and significantly increases ground clearance, fitting 33" tires with no trimming or 34" with nominal trimming.

We have options for all engine and transmission options years 2003-2023 and have just a few things left to confirm for the 2024 model. The spirit of this kit is similar to our standard conversion maintaining that all serviceable items are replaceable with widely available over-the-counter products. 

The conversion is an intuitive process and fully supported with a 130-150 page full color manual with images, mechanical drawings and torque specs. This kit comes with essentially every required part except fluids and parts to re-gear your existing rear differential. (We sell these separately.) 

Can I do this: 

Generally speaking, if you have a good familiarity with automobile service, some light fabrication or welding experience and a good space to work, yes. We don't recommend tackling this conversion without a vehicle lift. Many people have done it, but the product just comes out better if you have a friendly non-back-breaking spot to work out of. "Can this be done over a long weekend with a buddy?" Yes. "Will I be happy with my life choices on Monday AM?" No. Set a little time aside, a few weekends, and don't schedule a cross country family trip to visit your in-laws around the conversion. If all that resonates with you, this is totally do-able. 

Quick parts rundown:
  • 5-ish inches of lift, torsion bar tension dependent, 5" lift blocks standard, 6" rear lift leaf springs available.
  • Drop carriages for front suspension, OE lower control arms, custom adjustable uppers, custom knuckles, stock idler and pitman, modified tie-rod assembly, heavy duty skid plate.
  • Original van brakes, rotors, pads, ABS, so traction control presents almost zero complications* (Re-gear changes in 2021-2023 exceptions, call for details)
  • All wear items supported with OE or over-the-counter products, no Heim joints.
  • IFS design only, no solid axle GM conversions, 8.25" & 9.25" diff options, vehicle dependent. 
  • No transmission or fuel tank removing required (all variations.)
  • Manual shift NP261 transfer case, slip yoke output, automatic locking front hubs.
  • Cutaway / 4500 series vans require additional frame-boxing where the torsion bar carriage goes, heavy duty lift blocks we build, and we don't build rear driveshafts for non-standard wheelbases, but no further differences. 

If this is your first stop on our site, take a little bit to review the vans, resources, and information on our "How do I convert my van to 4x4" page. We also have answered a lot of frequently asked questions on our FAQ page. If you have further questions, we'd be happy to answer them by phone or Email. It is our goal to make the process as seamless and productive as possible and we've gone to a great deal to design a product that is field-tested and made for a pain-resistant install.  

    Included in kit:
    • Wood Crating + Flat Rate Shipping (Requires means to unload)
    • Comprehensive Color Manual (Specific to Vehicle) 125-150pg bound with torque specs and technique tips
    • Additional Misc - breather hoses, any templates or version-specific helper components available, EG: 6.6 Diesel includes some fuel line equipment, 6.6 Gas includes oil cooler lines. 
    Sample Installation Manual:

    Here's a sample of the first few pages, table of contents and content examples from one of the Hi-lift conversion manuals. 

    What info does Timberline need:

    Before or After making your purchase, please email us ( 720.515.5933 text ) with your vehicle information, VIN, any modifications, long/short wheelbase, front gear ratio required, any photos that are pertinent or other info. The more we have, the better we can serve you. 

    Fitment Designed for: 

    2003-2023 Chevrolet Express/GMC Savana 2500/3500, all engines + transmissions. 

    Tools Required:

    There is a list of suggested tools in the sample manual. 

    Gearing Recommendations:

    For 33"-34" tires (call to discuss if needed.) Most vans come with 3.42 gears, 3.73 was available in some years. 

    • 2.8 diesel 3.73 or 4.10
    • 4.3 gas 3.73 or 4.10
    • 4.8 gas 4.10
    • 6.0 gas 3.73 or 4.10 gas
    • 6.6 diesel 3.42 or 3.73
    • 6.6 gas 3.42 or 3.73
    • 6.6 gas 2024+ 3.42 or 3.73
    Tips / Skill Level:

    1-10 (10 being most difficult) Level 8. We like to equate the conversion to a slightly more involved job akin to a 6" 3/4 ton IFS GM lift kit with more cutting and some welding. Instead of 10 hours of work, it's more like 55, but we make it as easy as it can be. 

    Additional notes:

    CONTACT US with questions. Please read through this site, read through the FAQs, the product listings, and familiarize yourself with the conversion, you're going to have questions, we have answers, just let us know how we can help! 

    Price, Shipping, Fulfillment, Taxes, Quality and Returns
    • Shipping US: Turn-key kits ship LTL freight which is NOT INCLUDED in the purchase price. This setup is approximately 950lbs. We only ship these to commercial addresses with forklift or dock access. Typically $850 gets crating and shipping done anywhere in the contiguous US. High-congestion locations like SF & NYC or very rural locations can add a few hundred.
    • Shipping Canada / INTL: If you are in Canada, we ship direct and can handle brokering/GST. Typically it's another $150 plus 4.5% if you give us a company name. We frequently ship outside the US. Add $125 if your country requires certified Certificate of Origin docs (Canada does not.) 
    • Shipping/Fulfillment time for components: Turnkey Hi-lift kits typically take 3-4 weeks to palletize and ship, mainly due to axle/t-case build schedules. If you are working on a specific timeline, that is information we need up front. 
    • Taxes: Colorado residents must pay a sales tax of 7.5%. Phone orders on out-of-state sales do not require us to collect sales tax. 720 515 5933.
    • Quality and Returns:  We are consistently complimented on the quality of our products and the ease of installation. Fabricated components are generally hand-built here in Colorado by seasoned professionals. Replacement or aftermarket parts are only offered in high-grade options.

      If you are in any way disappointed in the components, we will issue a full refund less the cost of shipping when the product is returned within 30 days of receipt. 
      If you decide to return any components that didn't apply to your build or you changed your mind about, a shipping +15 % restocking fee will be deducted from the refund on parts. Turnkey kits are docked a 50% restocking fee if the kit is fully produced and on the pallet,