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Why Dual Transfer Cases?

      As our vehicles become more and more capable rigs, and after developing areas such as suspension, lockers and tires, we find our vehicles lacking in one area: Control and Gearing.
The lower your gears are, the more control you will have over your vehicle. With proper low gearing you will be able to "crawl" your vehicle over obstacles that you previously viewed as impossible!

      This is where our Dual Transfer Case kit comes into play. Our Adapter kit allows you to mate the reduction box portion of a NP203 transfer case to the stout NP205. The addition of the NP203 range box gives the option to run either transfer case independently in high or low (1:1, 2:1) or to run both in low (2:1 x 2:1) and DOUBLE your reduction for an astounding 4:1 low! Our kit mates factory NP203 and NP205 transfer cases, giving a wide array of vehicle application compatibility, not to mention the all-gear combination is capable of handling big block power! 

Read on, you'll come to find that the NorthWest FabWorks kit is far more than just average...
What Does The Kit Include?
Our Kit includes everything you need to bolt Your NP203 reduction box to Your NP205.
- NP203 Adapter Plate
- Center Clocking Ring
- NP205 Adapter
- 8620 Billet Intermediate Shaft
- PTO Cover with fill Plug
- Mounting and Clocking Hardware
- CR Seal & O-Rings
- Fiber Gaskets

What Else Do I Need?

On top of our kit you will need:

1 NP203 to mate to your transmission
- 1 NP205 with a 10, 27, 31 or short 32 spline input shaft
- A 2nd cross-member or custom cross-member
- A means to shift each transfer case from high to low range
- Modify your driveshafts to fit new driveline length

Which Transfer Cases Can I Adapt Together?
Are There Different Versions Of Each Transfer Case?
Our Adapter kit works with Ford, GM and Dodge applications. GM and Dodge use the same bolt pattern for the NP203, where Ford uses a different pattern. You will need a NP203 version that will bolt to your Transmission. NP203's are available from the factory in 10, 23, 27, 31, and 32 spline input, as well as divorced yoke input configurations.

Compatible NP205 Versions:

Figure 8
Our Adapter Kit is compatible with both large (90mm O.D) and small input bearing (80mm O.D) figure 8 style GM NP205's.

Large bearing GM Fig 8 NP205's are found from the factory behind 1980-1984 TH400's and are directly compatible with our 203/205 kit.

Small bearing GM Fig 8 NP205's are found behind TH350 automatics (27 spline) and SM465 manuals (10 Spline) until 1980. 

Both of these types of 205's are directly compatible with our 203/205 kit.

Large Bearing Dodge 205's (29 Spline Getrag 360 App.) must be swapped to a 31 spline Ford NP205 input or 32 spline GM 205 input to be compatible with our 203/205 kit. 

Small Bearing Dodge Fig 8 205's (23 Spline Auto App.) must be swapped out to a 10 or 27 spline GM 205 input, or bored out to 90mm and have a 31 or 32 spline input shaft installed.

GM and Ford 6 Bolt Round NP205
Our Adapter kit is compatible with the 6 bolt round pattern GM and Ford NP205 transfer cases. The GM round pattern case was found in 1985 and newer GM applications. These GM cases require an input gear swap to the short style input gear, but does not require the case to be bored out.

All married type Ford cases are short female 31 spline input with a 6 bolt round pattern.

What Are The Advantages Of The NorthWest Fab Kit?


Our Adapter kits can bolt ANY combination of Ford GM or Dodge NP203/NP205 together. There is NO upcharge for a weird combination at all! Since our adapters bolt together, if you require changing a transfer case in the future (ie. change your NP203 from ford to GM type) you do not need a whole new adapter, you only need to replace 1 of the adapter plates, its a minimal cost in comparison!

Blind Tapped Clocking Holes & O-Ring Seals:

The bolts that hold our adapter together are what is called "blind tapped" meaning the holes do not go all the way through the adapter plates, and thus no leak points. The center index ring of our adapter kit is sealed on both surfaces with a large O-ring, also eliminating any leak points.

Clocking Bolts Externally Mounted:

The bolts for Center Index ring are mounted outboard, and can be easily reached with a wrench. You do not need to completely disassemble the adapter to change clocking locations.

Precision Manufacturing:

Our Adapters are 100% CNC machined in Canada out of 6061-T6 Aluminum. They are NOT welded together, and as such are always perfectly parallel. The bolt patterns on all of our adapters are extremely accurate, and as such we run tight tolerances on all our parts.
Billet PTO Cover
 We now include a billet PTO cover with fill plug for your NP203 Range Box. These covers are anodized for lasting looks and etched with the NWF Logo. These covers are not welded - therefore always 100% flat. Only the best from NorthWest Fab.  


We offer everything you need, and we don't cut corners. You'll find everything you need right down to cut gaskets, breather fittings and all the hardware necessary for your installation.


The NP203 adapter plates are drilled and tapped to 1/2"NC at the base for easy mounting, the spacing matches a factory NP203 foot orientation. This allows the use of a 2nd crossmember to properly support the combo. 

Billet Mainshaft:

Our Kit includes an 8620 Billet mainshaft to connect your NP203 to the NP205. These shafts are heat treated 8620 gear steel; they are super strong and super tough and made at our shop in Canada. 

We do NOT respline factory shafts. With our kit you can drop the clutch in confidence!

**Our Billet Mainshafts are available separately for $349.00**

Tapped Adapter Holes:

Our adapter is tapped on the NP203 adaptor plate. This means you do NOT need one wrench on the bolt head and one on the nut. You simply tighten the bolts through the NP203 range box directly into the adapter. Its all in the details.

Finally, And Certainly Not Least, CLOCKABILITY

The NorthWest FabWorks Dual Transfer case is the most versatile adapter for sale today, nobody even comes close to offering the options that our adapter kit does.

First things first - What on earth is "clocking"? Clocking is the ability to mount (usually a transfer case in the 4x4 world) at different rotated position compared to stock. Rotating a transfer case up or down from the factory location has its advantages as well as downsides:

Clocking your transfer case up is often done as it easily increases ground clearance under your transfer case. However it will also create steeper driveline angles on your front driveshaft. Steeper driveline angles require expensive driveshafts to run at the required angle.

Clocking your transfer case down is sometimes necessary on vehicles with a large amount of lift. This is done to flatten driveline angles; however this is at the cost of ground clearance under your transfer case.

Although some of our competitors can offer their adapters in a clocked position (usually at an upcharge!) or allow you to weld an adapter into a fixed position, none offer a truly versatile clockable and re-clockable adapter. Our adapter allows our customers to mount their transfer cases in various positions to find what works best for them. At any point you can disassemble the adapter, change the rotation, and try the new position in your rig.

 The Heart Of The System: The Center Index Ring

 Clocking Is Useful, But What Are My Positioning Options?
Your first positioning choice is for your NP203 Range box. You Have 3 Options:

Option 1) You can mount your NP203 in the factory vertical position. This makes for the least amount of custom fabrication, as well is more compatible with factory adapters.

Option 2) You can mount your NP203 upside down from the stock position. This rotation will increase ground clearance, however a portion of the range box will enter the cab of the vehicle. Only a few factory adapters will allow this rotation to take place, and shifting the unit is slightly more complex.

Option 3) You can mount your NP203 90* to the right or left, (dependant on which side your rear transfer case has its front output on). Ideally you want the shifters to be located on the top of the range box, to avoid any potential leaks through the shifter. Slightly less floor modifications are necessary over the inverted setup. Again, most factory adapters will not work, and will require custom fabrication.

Your 2nd set of clocking options is for your NP205. There are many options:

The Center Index Ring allows your NP205 to be clocked from 0 to 6.5" up or down in as small as 0.5" increments. Meaning you can rotate your transfer case to find whatever fits YOUR needs best! Nobody else can even come close to giving you these options. Not to mention you can disassemble the kit and change your clocking position whenever you like!

It does not matter if you have a passenger or drivers side drop transfer case, you will still be able to clock your transfer case as you need.

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