IFS 4x4 Van Conversions
GM g-series
Research
Here, you can explore the different types of GM 4x4 van conversion kits we offer, see what’s included in our standard core kit, and identify the remaining components needed to complete your 4x4 conversion.
Our Turnkey GM kits take the guesswork out of sourcing those additional new and used components so you can just pull the van on the rack and knock out the swap.
Core kit
This is our standardized G-Series 4x4 van conversion kit, available for vans from 2003-current with all engine options. Our designs work with 2500, 3500, and 4500 series vans in all configurations, including cab and chassis models. GM 4x4 conversions have more variations and constraints than Ford vans, but we've addressed all the variations and are here to make sure you don't get in trouble.
We offer two lift height options, both featuring independent front suspension torsion bar designs, similar to Silverado pickups. The standard lift provides 0-2.5" of lift, which can be adjusted with lift blocks and torsion keys.
Our Hi-Lift option requires substantially more parts but still uses mostly OE-type wear components, making it easy to maintain your lifted 4x4 van with over-the-counter products.
Both our core and turnkey kits come with a printed and bound color manual that details every aspect of the build process, specific to your vehicle and conversion options.
Below, you will find a list of included components and additional parts required to complete the conversion.
Turnkey Kit
Our turnkey GM kits are a popular solution for van people with limited time and shops completing the installation. It's convenient to open up a crate and get right to work, knowing you'll have all the components required to complete your 4x4 conversion.
These kits include everything listed in the core kit, along with shocks, a pre-clearanced front differential and transfer case, driveshafts, and other miscellaneous new or reconditioned parts needed to complete the build. Our prices on over-the-counter components are competitive, and even the retail parts are inspected prior to packaging. This is the easiest way to get everything you need ready to roll.
|
Kit / Part
|
Notes
|
|---|---|
|
Front differential system
|
Bracket, bushing, frame modification components to hang front 4x4 axle.
|
|
Steering centerlink
|
Modified steering linkage for diff clearance
|
|
Transmission 4x4 conversion system
|
All GM transmission conversions are done without removing from vehicle.
|
|
Rear end kit
|
Standard kit includes lift blocks (if applicable), and rear U-bolts.
|
|
Transfer case shifter kit
|
Manual shifter assembly.
|
|
Front sway bar mod kit
|
Bar spacers, new sway bar links, lower mounting tabs
|
|
Bump stop kit
|
New bump stops & brackets for front
|
|
Front hub ring adapters
|
Centers truck hub to integrate with van knuckles and brake calipers
|
|
Torsion bar carriage system
|
Does not include bars or keys
|
|
Front diff motor lock & 4x4 range LED indicator harness.
|
Can save hours of wiring frustration
|
|
Installation master manual
|
Printed full-color bound manual
|
|
Helper kit
|
Steel it chassis paint can (the good stuff), thread locker, anti-seize, witness marker, paint pen, extra zip ties, frame-cut welding shield(wood), 9/16" cobalt bit
|
|
Fuel tank blank
|
Shortening blank for vans that require
|
Timberline Core Kit Inclusions
Gm G-series 4x4 conversion 2003-current (2500/3500/4500)
This section includes parts included in the "Core Kit" and vary slightly by year/model.
|
Transfer Case
|
Notes
|
|---|---|
|
NP261 29 Spline Input (6L90 transmissions)**
|
2001-2006 K2500/3500 XHD 8.1/6.6 Diesel engine trucks
|
|
NP261 31 Spline Input (4L80/8L90-MTH/N8X) transmissions
|
2001-2006 K1500/2500/3500 non 8.1 gas engine trucks
|
|
NP241
|
Slightly more chassis feedback than 261
|
|
NP242
|
Hummer H1 Liquid cooled AWD transfer case, full time AWD
|
|
NP246
|
Manual conversion available
|
|
MP1225
|
Magna T-case, not our favorite choice
|
Transfer Case
T-case usage varies by transmission. We prefer 261 case, however there are many other cases that interface with GM vans and our components.
**LD case can be used by changing out input shaft without sourcing a complete $$ XHD case
|
Front Axle
|
Notes
|
|---|---|
|
8.25" front differential
|
2007.5-2020 Silverado/Sierra 1500. Options for 3.42, 3.73 and 4.10 widely available
|
|
9.25" front differential
|
1999-2010 Silverado/Sierra 2500/3500. Recommend 2007-2010, Options for 3.73 and 4.10. Re-gear kits available to change to 3.42
|
Front differential
Most vans are 3.42 gear ratio. Many people regear their vans when choosing front diff ratio. Regearing on 2021+ vans presents challenges.
|
Part
|
Notes
|
|---|---|
|
Front shocks
|
Can be reused from van, Hi-lift vans require new shocks (Bilstein 5100)
|
|
Rear shocks
|
Can be reused from van with shock extensions, Hi-lift vans require new shocks (5100)
|
|
Torsion bar keys
|
Even GM has updated their clocking of these keys, we recommend new
|
|
Lower control arms
|
1999-2010 Silverado/Sierra 2500/3500. 01-early 07 1/2 ton
|
|
Transmission Mount
|
|
|
CV Axles
|
Varies per project, all over-the-counter. We always use high angle new Axles
|
|
Front hub assemblies
|
07-10 Silverado/Sierra 2500/3500. Some other K-hubs may work
|
We recommend replacing these on all new builds, however it's common for budget-minded users to upcycle parts from available parts trucks.
Recommended New Parts
|
Part
|
Notes
|
|---|---|
|
Torsion bars used
|
GK,GL,XG only 1999-2010 K2500/3500
|
|
Sway away torsion bars
|
New option, additional adjustment, more $$
|
|
Torsion bar keys
|
No longer made by GM, these are generally sourced used or aftermarket. It's very important to use the heavy weight rated bars on all vans.
Torsion Bars
|
Part
|
Notes
|
|---|---|
|
Front Driveshaft
|
Can be "re-tubed" from stock 2001-2006 GM trucks
|
|
Rear Driveshaft
|
We always build 1-piece design for standard SWB/LWB vans
|
Driveshafts are build to order. Currently all 8-speed transmission van driveshafts require measurements from customer to build. Lead times are short.
Driveshafts
|
Kit / Part
|
Notes
|
|---|---|
|
Front differential system
|
Style and fit different than standard lift
|
|
Adjustable upper control arms
|
Required to use truck lift knuckles
|
|
Front lift knuckles
|
Unmodified K-series knuckles will cause steering issues.
|
|
Bump stop kit
|
Different brackets for Hi-lift
|
|
Lift carriages
|
Front and main. Typical aftermarket truck lift carriages do not bolt up
|
|
Skid plate
|
Diff protection
|
|
HD tie rod kit
|
Utilizes HD aftermarket truck tie rods for improved range/durability
|
|
Custom rear leaf packs
|
Recommended on all Hi-lift vans, 6-8 week lead time, build to order (weight/lift)
|
|
Limit straps
|
|
|
Rear brake line extensions
|
Rear brake line extensions
|
|
Sway bar links
|
Buy extra bushings, all vans love to eat them
|
Hi-Lift Requirements
These vary per project. Hi lift vans require 17" rims, Typical tire size 33", will not fit 35" without clearance mods. Overall lift is 5-6" suspension.
If you would like a more detailed build sheet for your specific vehicle, you may fill out the form below and we will send you a link to view one. Please allow 48 hours as these are processed manually. Please note! These sheets are not designed for mobile. If you do not have access to a laptop or desktop they will be of no use to you.
