2500/3500 series GM Conversions

--Update March 2020 --

-Currently, we offer a 4x4 conversion for 2009-2019 Chevy Express / GMC Savana 2500/3500 series non-cab/chassis models with 4.8/5.3/6.0 gas-powered engines only.

--We have 2 cab and chassis variants here for conversion that will be completed in April, so the CC models will be added shortly. One of them is an earlier model, which will makeup the 2003-2008 options, which will be added.

-We do have capacity to do the 4.3 models, however it does add significant expense.

-We have completed a 6.6 Duramax and the bulk of the work on the 2.8 Duramax, however, to fine-tune these options we are asking for a little more time to properly develop them. If you have requests outside the gas 09-19 models please email or call.

-Our conversion kit for the GM product is available for purchase, however, we have some constraints and disclaimers, so please email or call if you'd like more info.


Most common answers:


-3" lift only, max tire size is 265 70 17. We do not offer a 35" tire option currently

-OEM wheels and tires will work, aftermarket/higher offset wheels available

-Approx 2-3 week turn around

-Scheduling varies, call for details

-Currently gas engine 2009+ model non-cab/chassis vehicles (cargo/passenger ok)

-Upfitting and reconditioning available, we typically stop at cabinets and bed platforms

-IFS front suspension design with 2 speed high/low 4x4 manual transfer case, automatic locking hubs

We have a pretty good breakdown of the process for having your van converted to 4x4 on our CONVERT MY VAN page. 

build (GM)

About our conversion:

Our IFS GM van is designed around factory parts and we fabricated the remaining components to be similar to what GM would've done had they made a 4x4 1 ton van. This rig features a high/low 2 speed transfer case, option of 0" to 3" lift over stock, and from OEM 245 75 16 to modest 265 70 17 series tires. 

All fabricated components are powdercoated for longevity, or epoxy painted post weld-in. Our GM vans drive basically like a conventional 2 wheel drive van, and when we upfit to a slightly larger tire size we usually opt to re-gear accordingly so even the 4.8 gas vans run circles around many Fords.


The GM van is easy to get in and out of and has similar ground clearance to a crew chevy pickup. All 4x4 components are 1 ton design or larger, 2-3 times the size of what you'd see on an AWD G1500 van. Vehicle can be easily serviced at any normal shop, maintains factory anti-lock brakes and traction control systems, and we will provide you with a build sheet for all serviceable items so you know exactly what parts you need to keep it on the road for years to come. 


Important stuff

Service: Vehicle can be easily serviced at any GM dealer or conventional mechanic

Parts List: Parts list of serviceable items provided on every vehicle, so you know what you have in the future

Front End: Independent front suspension, 2500/3500 series 3rd Member (remanufactured) 3.42/3.73/4.10 gear opt.

Transfer Case: Manual shift NP261 (NV261) from 1 ton K series truck

Transmission: Unchanged, precision machined steel adapters, powdercoat, hardened chromoly spline shaft adapter

Stability: Design does not impact ride stability, heavy duty sway bars available.

ABS, TCS, RSC, ETC: Factory ABS and stability systems maintain functionality across all sub-models

Emissions/Smog: All factory emissions equipment across all sub-models remains functional

Parts: Serviceable components are all off the shelf parts available OEM or aftermarket equivalent

Lift: Zero and 3" lift options

Tires: 245 75 16 up to 265 70 17 recommended, 275 70 18 will likely fit with zero offset wheels and some trimming

What's included

New parts: New front hub assemblies (Moog, Timken or SKF), custom CV axles, brake rotors, brake pads, lower control arms with ball joints (Moog), Moog torsion keys and hardware, rebuilt NP261, steel front driveshaft, aluminum single-piece rear driveshaft, all new grade 10 hardware/bushings, manual shift t-case with automatic locking hubs (electric), 4x4 indicator lamp, custom t-case linkages, new lever and ball.


Notes: All hardware for conversion is grade 10 and grade 8 certified with zinc coating where available. Conversion does not require new wheels or tires, but most people opt to change them during conversion. Timberline requires 8/32 minimum even tread on tires if you intend to re-use them. OEM TPMS system remains functional. All fabricated components are powdercoated for longevity and salty climates. Heavily welded-in components will be epoxy painted by hand before vehicle is assembled as powdercoat is burned off during install. Conversion includes fresh alignment. 


Remanufactured: Torsion bars, front differential, rear differential (3.73/4.10 gears)

Warranty: Our outside conversions come with a 12 month 12,000 mile parts warranty. Labor is included for Colorado customers only. Parts warranty is limited to manufacturer or installation defect. 

What we work on

Van Condition: We generally prefer to work on nice non-rusty vans. It doesn't make sense to spend a lot of money on a dilapidated vehicle. We realize all vans are used and have personality. 

Additional Upfit / Labor / Payment

Additional labor rates

-Shop Rate + Mechanical Work: $95/hour (my van needs spark plugs, I want a power inverter and solar)

-Specialty Diag / Custom Labor + Fab: $115+/hour (my left turn signal causes my radio to play country, I need a built-in fish tank)

Payment: On a conventional conversion, we require $9,000 down at the time of van being dropped off. The balance is due on delivery. If you have additional upfit requirements, additional down will be required. Non-Colorado residents must pay balance with certified funds, cash, or credit/debit. We accept all major credit cards, however, there is a 2% charge for anything more than $4,000. Colorado residents must pay tax on applicable parts.


When your van is finished, you can schedule a pickup which only takes about 20 minutes. If you are out of state and want your van delivered we can help with that. We also offer free airport pickup if you'd like to fly in and drive your van home. If you need some time to get here, we can store the van for you for up to 30 days. Additional storage of vehicle may incur fees as we are limited on space.

You will receive a build sheet with the details of your conversion components for future service and we will spend whatever time you need to explain your new setup. We generally take folks on a quick 5-10 minute test drive to go over the 4x4. Balance due by cash, certified funds or debit card for balance. Credit card payment fee schedule same as at drop-off.

Colorado Residents:

Timberline will collect applicable sales tax on parts used in the conversion process. A good deal of the components used already have taxes paid on materials. 

We offer a free 1000 mile checkup on your van, just to bring it in and shake it down, check for any details needing attention. If you are in metro Denver, we offer free pickup and delivery service of your van.

16015 W 4th Ave Suite 1 Golden Colorado 80401

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© 2019 by Timberline Vans