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4/10/24 - Timberline will have limited fulfillment on core/turnkey kits for May. April has been filled. We have 2 spots in May, and further larger orders will likely ship in June when normall fulfillment continues. Smaller orders on 1-5 pieces shouldn't have too many hold ups. We appreciate your business and are working hard to keep up! 720-515-5933. Thanks!
4/10/24 - Timberline will have limited fulfillment on core/turnkey kits for May. April has been filled. We have 2 spots in May, and further larger orders will likely ship in June when normall fulfillment continues. Smaller orders on 1-5 pieces shouldn't have too many hold ups. We appreciate your business and are working hard to keep up! 720-515-5933. Thanks!
Timberline 4x4 GM Van

G-Series 4x4 Conversions

Parts

In this section, you will find a list of our available parts for GM 4x4 conversions. Please click the tabs above for more info and resources. 

Info

The Chevrolet Express / GMC Savana platform is an excellent choice for 4x4 van conversions. The body on frame design is widely available and still produced today. 

The setup is ideal for IFS suspension conversion which gives these vans comfortable drivability akin to a factory 2WD van.

They are inexpensive to work on, extremely durable, and parts are widely available. Timberline offers 2 lift variants of this conversion, a 1-2.5" suspension lift and a 6" lift option. 

Unlike the Econoline, the G-Series van is offered in 2 wheelbases, 138" and 158". The long-wheelbase version can be a little more challenging to park. The G-series is not available with a high top from the factory. Cab and chassis models obviously open up box-truck type options.

Options

-We currently have conversion options for the 2003-2021 G2500, G3500, and G4500 series models. (We do not offer a 4x4 conversion for 1/2 ton models)

-Transmission options are limited to the 4L80, 6L90, and 8L90 variants. We have not attempted to convert the 4L60 to 4x4, found on some earlier 2500 models. All Timberline GM transmission options can be completed without the removal of the transmission from the vehicle. 

-If completed properly, a standard lift option conversion should drive nearly identical to the van prior to conversion. 6" lift variants will drive very very well, however raising the center of gravity and installing 34" tires on anything will change the vehicle behavior to some degree. (Cool factor + clearance increases substantially more than ride quality degradation, if you want the lift, get the lift.)

Difficulty

-The GM IFS 4x4 torsion bar conversion is slightly more invasive than the Ford E-series, however, we have worked very hard to produce an easily repeatable, reliable 1-way solution that works every time. 

-The GM IFS conversion requires cutting and some welding. It is meant to be completed in a shop and with both automotive and some light fabrication experience. Everything is very straightforward and basically only fits one way, so if you can follow simple instructions with clear photos, you'll be fine. A plasma cutter is not required, however, it does make some of the work go more quickly. 

Resources

Please visit our "how do I convert my van to 4x4" page for a good overview of the options, process, and budgeting. 

 

  • from $250.00

    4L80 Manual Transfer Case Shifter Kit

    Description This is a bolt-up manual transfer case shifter for the 4L80 transmission found in many GM pickups and vans. Our shifter is designed to...

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    from $250.00
  • from $199.00

    6L90 Manual Transfer Case Shifter Kit

    Description This is a bolt-up manual transfer case shifter for the 6L80 transmission found in many GM pickups and vans. Our shifter is designed to...

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    from $199.00
  • 4x4 Timberline 6L90 Kit
    from $1,795.00

    6L90 Bolt-up 4x4 Conversion Kit (no-cut)

    Description: This is a straightforward bolt-up solution for converting your 6L90 transmission to 4x4, without the need to cut the output shaft. To ...

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    from $1,795.00
  • 2WD to 4x4 4L80 Conversion Adapter
    from $595.00

    4L80 4x4 Conversion Adapter Kit (no-cut)

    Description: This is a straightforward bolt-on solution for converting your 4L80 transmission to 4x4, without the need to cut the output shaft. To ...

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    from $595.00
  • $99.00

    4L80 4x4 Extension Housing GM OE Aluminum

    Description: This is a GM performance or ACDelco OE Aluminum 4x4 extension housing compatible with 1999-2007 Silverado 2500 + 3500 vehicles & S...

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    $99.00
  • Torsion Bar Carriage 4x4 GM Van
    from $885.00

    GM 4x4 Van Torsion Bar Carriage System

    Description: This torsion bar carriage and transmission/t-case cross-member is designed for use in 2500 + 3500 series Chevy Express and GMC Savana ...

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    from $885.00
  • $1,650.00

    NP261 Rebuilt Transfer Case for 4x4 Van Conversions

    Description: The NP261 was built by New Process (New Venture) and is a reliable chain-driven transfer case used primarily in Chevrolet and GMC veh...

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    $1,650.00
  • $379.00

    8L90 Bolt-Up 4x4 Conversion Kit

    Description: This is the component kit required to convert a 2-wheel drive 8L90 transmission to 4x4. This conversion can be performed in-vehicle wi...

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    $379.00