GM Van 4x4 Core Conversion Kit Standard Lift

Description:

This is the Timberline core components kit required to convert your 2500 or 3500 series GM van to 4-wheel-drive. We have worked diligently to compile standardized kits for many different variations of engines, transmissions, and changes throughout the 2003-2023 year model vans. 

We provide both core and turn-key conversion kits for these vans. The core kit basically solves for all the non-over-the-counter parts you wouldn't want to build from scratch or design with the hopes of getting it right the first go. 

Some of you will only want specific parts we sell, which is why we offer everything a la carte. That said, this kit is the first step in cutting your design and build time way down.

Standard Lift = 2-3" of Lift, 265 75r16 or 265 70r17 tire size recommended.

How does this work?

1) Start with the FAQ section and GM Design pages will help you wrap your head around everything that goes into this process and at some point you'll want to visit the How-to section, particularly if this is a new concept for you. Call us for a consult if you have questions. 720-515-5933.

2) Choose the kit type from our available options and if you like, email us over your VIN number and a few photos of your van for a more detailed build sheet, mentioning what kit you'd like to work with. 

3) Order your parts either from our site, or we can send you a checkout link or pay by phone/mobile. 

4) Source your remaining parts and assemble your axle while we wrap up your kit and ship it to you, and once it arrives you can get right to work! 

What vans, differential, t-case

Vans:
2003-2024 GMC Savana/Chevrolet Express 2500/3500/4500 Vans Only (All Engines All Transmissions)
Front Diff Options:
8.25" - 2008-2018 GMC Sierra / Chevrolet Silverado 1500, Suburban, Yukon, Tahoe, etc, typical compatible gearing 3.42, 3.73, 4.10
9.25" - 1999-2010 GMC Sierra / Chevrolet Silverado 2500/3500, Suburban 2500. Recommended 2007.5-2010 years. OE Gearing 3.73/4.10. 3.42 will require changing ring and pinion which we can provide.
T-Case:
Preferred: 2001-Early 2007 Silverado/Sierra NP261,1500,2500,3500 solutions
Other: 29 and 32 spline input GM friendly 6-bolt cases, NP241, NP205, NP263, MP1222, MP1226, MP2225 AWD

Model Specific Notes:

Fuel Tanks / Trans:
Unlike Ford, no fuel tank shortening, exhaust re-routing, or transmission removal in any models. 

Transmissions:
4L80 - Inexpensive to cut output shaft and just hang the t-case directly or use our adapter for no-cut option.
6L90 - More costly bolt-up 4x4 adapters from Timberline, no transmission disassembly required.
8L90 - Conversion parts available from us, can be done in-vehicle.

4.8/6.0 Gas: Generally the most straightforward of the lot. We have both 8.25"/9.25" diff options, motor mounts can be trimmed in-body, relatively easy clearances.

6.6 Gas: more light-duty fabrication work than other models. We recommend buying our pre-modded motor mounts which clearly outline clearance requirements. 8.25" differential is required for standard lift and recommended for hi-lift. 9.25" can be installed in hi-lift using 2007-2010.5 front diff and our custom oil cooler lines.

6.6 Diesel: pre-2012 models will only fit 8.25" diff with standard lift without oil pan modifications which we don't support. 2012-2016 vans with 6.6 will fit 2007.5-2010 but it's very tight. Hi-lift 4x4 vans will fit 9.25" without issue. Additional fuel filter relocation requirements. 

4.3 Gas: 8.25" differential in standard lift, though notching aluminum oil pan will fit 9.25". Hi-lift 4x4 vans will fit 9.25" without issue. We don't support any pre-2017 4.3 Vans.

2.8 Diesel: Most time-consuming but it's totally doable. We recommend our pre-modded motor mounts which cut down on fab time and are easily accessible. 8.25" differential only. Passenger diff mount, exhaust hangars, and fuel filter relocation all require general fabrication skills. Don't try to flatback this one in your driveway. 

What is the hardest part?:

Installing the front diff in a van is the most technical aspect of the conversion, but it's very straightforward and repeatable with our kits. Recommended tools include: a vehicle lift, plasma cutter, and some welding ability. Can this be done with an angle grinder, stick welder and jack stands? Absolutely, but expect a reduction in the joy factor. 

There is some cutting around the motor mount brackets and work required to relocate the main cross member rearward. We provide metal cut templates for everything and detailed instructions. The nature of the installation is intuitive if you follow the directions and look at the photos. With both 8.25" and 9.25" differentials, installation begins with 1-2 static brackets, and the remaining 1-2 are located using the diff itself. This ensures clearance, leveling, and fitment prior to permanent welds. 

We have sold many of these kits and the questions never seem to be about this part of the installation. The most common current questions we get are people asking us to send more components of the turn-key kit. 

Manual Sample:

Here are some sample pages from our GM 4x4 conversion manual. Our manuals include detailed photography, mechanical drawings, torque specs, and helpful tips.

We are dedicated to making the process as straightforward and easy as possible.

Included in kit:

• 4x4 IFS Front Differential Mounting System
• Transmission 4x4 Conversion Kit (4L80, 6L90, 8L90)
• Transfer Case Shiter Kit (4L80,6L90,8L90)
• Hi Clearance GM Center Link ($125 core)
• Rear Lift Kit (Shocks not included)
• Easy-Wire GM Hub Lock & Indicator Kit with AAM motor
• Sway Bar Kit
• Front Shock Adapter Kit
• Front Hub Adapter Rings
• Bump Stop Kit
• Timberline Helper Kit
• Torsion Bar Carriage System
• All Applicable Hardware
• Detailed Full Color Printed/Bound Manual

What else do I need:

• Front & Rear Shocks
• Torsion Bars
• Torsion Keys
• 4x4 Hub Assemblies
• Lower Control Arms
• Trans Mount
• CV Axles
• Transfer Case
• Front Carrier (Diff)
• Front & Rear Driveshafts

Tools Required:

We have a standard list of tools that we recommend listed in the front of our manual and the GM Design. It's pretty basic stuff, if you have your own workshop with a lift, you probably have nearly all of them. 

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, only instead of 10 hours of work, it's more like 35-55 depending on your conversion

This product may work with other model vehicles. 

Price, Shipping, Fulfillment, Taxes, Quality and Returns

• Price + Shipping: Core-kit flat-rate shipping to the lower 48 is $330 currently. Residential delivery and lift gate service add $90 each so try to work out a commercial delivery address with 2 big humans or a forklift, most kits weigh 200-250lbs.
  
  
• We have a Canadian export license and can ship directly to customers as well as handle duties. Alaska, Hawaii, and International shipping is available on request. Typically Canadian GST is 4.5% for businesses and 10% for private individuals. We are charged a $125 brokering fee for Canadian LTL shipments. Due to vast expanse of the great north, shipping and orders must be processed manually for Canadian customers. 
  
  
• Shipping time for full kits: Timberline produces parts and kits on a block schedule listed on the main home-page. Order periods are book-ended at present to ensure consistent fulfillment times. Typically full kits fulfill in 4-8 weeks depending on where in line your order is placed. 
  
  
• Taxes: Colorado residents must pay sales tax of 7.5%, no sales tax is collected on out-of-state shipments currently. 
  
  
• Quality and Returns: We are consistently complimented on the quality of our products and the ease of install. Components are hand-built here almost exclusively in Colorado by seasoned professionals who are fanatics about design and execution.
  
  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. If you decide to return any components that didn't apply to your build or you changed your mind about, shipping and a 15% restocking fee will be deducted from the purchase refund.