STaK 4x4's Dana 300 Replace-A-Case has put the Dana 300 transfer case in the same class as GM's 350 small-block V8, where used donor parts such the 350's block or the 300's housing are no longer required for assembly. With a diminishing amount of usable Dana 300 donor housings available in wrecking yards these days (the Dana 300 hasn't been used in a production vehicle since 1986), the Dana 300 Replace-A-Case effectively extends the life of this stout geardriven transfer case that has dutifully served in multiple makes of 4x4s during its multiple-year span of production.
The Dana 300 Replace-A-Case consists of two case halves that are manufactured from cast 356 alloy aluminum and then hardened to a T6 condition. Each case half offers thick walls to hold up against case deflection under hard acceleration. In order to maintain tight tolerances throughout the assembly, the profiles of the case halves and all bearing locations are fully CNC-machined to exacting specifications. The case halves are joined using 3/8-16 stainless steel socket-head cap screws to ensure positive attachment and further increase the unit's strength.
In addition to bringing more overall strength to the Dana 300, the STaK 4x4 Replace-A-Case is impressively versatile. Its design allows it to be used as a direct replacement for less desirable chaindriven transfer cases such as the NP231 in Jeep YJs and TJs. This is achieved without using the common method of mounting the Dana 300 upside down to turn it into a driver-side drop transfer case. Several clocking positions are already in place on the Replace-A-Case to suit the mounting needs of many applications, and many different input splines are also available. When used to replace an NP231 transfer case in Jeep TJs and YJs, the Dana 300 adds approximately 9-1/2 inches to rear-driveshaft length, which will effectively decrease the operating angle of the rear driveshaft in these short-wheelbase rigs. The Replace-A-Case accommodates the factory TJ and YJ speedometer-sending units, and STaK offers a TJ-style shifter that's designed to fit through the factory hole in the transmission tunnel as well. A universal shifter is available to suit other applications and can be modified as needed to meet most needs. STaK can also provide adapters to mate the Dana 300 to most GM, Ford, and Jeep applications.
Multiple clocking patterns are built into the Replace-A-Case to suit various mounting positions for numerous applications. Brass bushings are used to support the new shift rods. | 
The case halves use extra-thick walls to withstand case deflection under heavy acceleration. For assembly, the halves are securely located on four dowl pins, with one upper pin and one lower pin in each case half. | 
We'll use the Replace-A-Case and this built Dana 300 to create the ultimate durable transfer case. Within the Dana 300 on the right are 4:1 LoMax gears and heavy-duty front and rear outputs. Combined, these two units will become a very strong link in the driveline. |