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.
4L80 Manual Transfer Case Shifter Kit
Timberline SupplyDescription This is a universal bolt-up manual transfer case shifter for the 4L80 transmission found in GM trucks and vans. The kit is optimized fo...
View full details6L90 Manual Transfer Case Shifter Kit
Timberline SupplyDescription 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...
View full details6L90 Transmission Bolt Up 4x4 Conversion Kit
Timberline SupplyDescription: This is our updated high-performance adapter setup for converting the 2 wheel drive 6L90 to 4x4 without cutting anything. Our beautifu...
View full detailsEasy-wire GM 4x4 hub lock + Indicator Kit
Timberline SupplyDescription: The Easy-wire GM 4x4 hub lock + indicator kit is a stand-alone wiring system designed to activate the front hub lock motor and LED ind...
View full details4L80 4x4 Conversion Adapter Kit (no-cut)
Timberline SupplyDescription: This is a straightforward bolt-on solution for converting your 4L80 transmission to 4x4, without the need to cut the output shaft. To ...
View full details4L80 4x4 Extension Housing GM OE Aluminum
Timberline SupplyDescription: This is a GM performance or ACDelco OE Aluminum 4x4 extension housing compatible with 1999-2007 Silverado 2500 + 3500 vehicles & S...
View full detailsGM 4x4 Van Torsion Bar Carriage System
Timberline SupplyDescription: This torsion bar carriage and transmission/t-case cross-member is designed for use in 2500 + 3500 series Chevy Express and GMC Savana ...
View full detailsEasy-Wire Transfer Case Range LED Indicator Kit
Timberline SupplyDescription: Take the head-scratching out of wiring up the indicator for your transfer case. This is our Easy-Wire kit that cuts way down on time t...
View full detailsNP261 Rebuilt Transfer Case for 4x4 Van Conversions
Timberline SupplyDescription: The NP261 was built by New Process (New Venture) and is a reliable chain-driven transfer case used primarily in Chevrolet and GMC veh...
View full details4L60 & 4L65 Manual Transfer Case Shifter Kit
Timberline SupplyDescription This is a universal bolt-up manual transfer case shifter for the 4L60/4L65 transmission found in GM trucks and vans from 1992-2013. The...
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