Complete SM420
Transmission Package

The SM420 is a legend, and remains one of the greatest Jeep conversion transmissions of all-time.

Our Muncie 420 is professionally and meticulously rebuilt. We use the best components, including bearings, synchronizers, bushings, seals and gaskets built by our SM420 specialist and expert. Any required updates and improvements are performed.

The 420 will be built using a GM style mainshaft or a Novak conversion mainshaft, as per your application. Included and installed is the Novak transfer case adapter and crossmember urethane mount assembly.

A new, unbent transmission shifter cane is included and ready for the installer to bend to the particular application and driver's preference (if you wish you use your factory stick, let us know and we'll apply a discount).

Adapted Builds
The 420 will be built with a Novak conversion mainshaft, the Novak transfer case adapter and crossmember urethane mount assembly.

An example of a Novak adapter, installed and ready.

Transfer Case Adaptability
Your 420 can be ordered ready to join to the following Jeep transfer cases:

• Dana 18, 1941-1971

• Dana 20, 1962-1979

• Dana 300, 1980-1986

• New Process Jeep 208, 219 & 229

• New Process 207, 231, 241OR, 242 & 249

We can also do a full rebuild of your Jeep transfer case if you would like to ship it to us. We can provide any upgrade components for it that you wish. It will be pre-installed to the transmission and ready to lift into your Jeep.

Factory Style Builds
We also can provide factory style 420 transmissions for faithful GM truck restorations or upgrades. We also perform rebuilds on industrial and military SM420 transmissions.

Your SM420's Construction: We start with a good core transmission and do a full disassembly and breakdown Detailed parts inspection and measurement is performed The main case and top cover are hot-cleaned, media blasted, primed and enameled with a tough, industrial grade finish The top shifter cover is fully rebuilt with new springs, poppets and hardware Full gearbox reassembly using all new bearings, bushings, syncrhonizers, snap rings - all consumable transmission parts - are replaced and new hard parts are installed wherever indicated A new reverse switch is installed, even on models that originally didn't feature one Your transfer case and bellhousing (if available) are installed and configured

Bellhousing Compatability
We will also configure your front input section for a variety of OEM or conversion bellhousings including:

• GM 4-11/16" bore bellhousings

• GM 5-1/8" bore bellhousings

• AMC I6 (258 & 4.0L) & V8 bellhousings

We can often source a bellhousing or use your particular GM or AMC bellhousing as required. Conversions to AMC bellhousings will include necessary machining for Crank Position Sensors (CPS), face pockets (if necessary) and the bellhousing rear face bolt pattern. The pilot bushing is included as specified.

Logistics
Your SM420 package will arrive at a location of your choosing (preferably a business location with a dock / forklift), palleted and ready to bolt into your application.

Pricing
Pricing is generally as follows:

• SM420 with a Novak adapter assembly, to GM engines, including pilot bushing, a new straight shifter stick and urethane mount: $1620.
• SM420 with a Novak adapter assembly, to AMC engines, including special front retainer and pilot bushing, a new straight shifter stick and urethane mount: $1710.
• SM420 factory style build: $1120.

Individuals considering the SM420 for most conversion situations might alternatively consider the more modern and more affordable SM465 transmission package.

Order
Because of the many variations involved, we encourage you to contact us directly by phone or e-mail. We will help you put together your transmission to best fit your requirements.

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