Adapting
AMC I6 & V8 Engines
to the
Chevrolet / GM Hydramatic Transmissions
Widely considered to be the best automatic transmissions in the world, General Motors HydraMatics make for outstanding upgrades into Jeep powertrains. This adapter assembly brings the Jeep / AMC 232, 258, 304 & 360 engines together with Chevrolet style automatic transmissions, including the TH350, TH400, TH700R4, 4L60, and Early 4L60-E* transmissions.
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The Adapter
This plate style adapter is precision laser cut and machined. Included are the crank spacer, flexplate, flexplate spacers, flexplate reinforcement ring and fastening hardware. Additionally, we include a shield plate with a convenient access port for your torque converter bolts.
Precision CMM mapped and machined dowel locators and fastening points assure total concentricity for long transmission and torque converter life.
The adapter is plated in black zinc for corrosion resistance and appearance.
Transmission Versions
The Chevrolet style HydraMatic transmissions, including the:
*The electronically controlled Early 4L60E will require a transmission control unit, which - while effective - are somewhat expensive. The installer should instead consider the conventionally controlled 700R4.
The Later Style 4L60-E (removeable bellhousing, hex rear bolt pattern) are not candidates for this conversion.
The TH350 is the only candidate for 1972-1983 CJ5 Jeeps due to their length, and these Jeeps must not have excessive lifts.
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Engines
All 1972-on AMC engines, including the:
For the 1991-2004 Mopar 4.0L engines use our #437AMC-5 kit as seen here. For Renix era (1987-1990) 4.0L and Mopar SFI 4.0L engines, you may choose the 258 version of this kit and use an aftermarket Crank Position Sensor relocation kit.
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As for V8 installations, be aware that the passenger side exhaust flange on rear-dump manifolds or headers may interfere slightly with the transmission flange in a small area. Deburring this flange may be necessary for your installation.
Installation
The adapter is easily and quickly installed onto the engine and transmission. The installer will need to pay attention to the flexplate to torque converter spacing and shim as appropriate (shims included).
You will use your existing AMC starter.
Your Torque Converter
The grand majority of GM torque converters have the standard size three-bolt pattern that is 10.7" on diameter. However, some factory or aftermarket heavy-duty TH400 torque converters (as seen in RV and heavier truck applications) may use a larger bolt pattern diameter, which is not compatible with our particular flexplate that is included with this kit. You may wish to exchange this converter towards one with the standard diameter bolt pattern. The converter can be rated at any duty or stall you wish.
Engines & Engine Mounting
In essentially all installations, these factory Jeep engines will remain in their original locations.
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| Our RadLock radiators offer a highly efficient and extremely durable cooling solution for most AMC engines, and incorporate an auto transmission cooler for your new HydraMatic. |
Engine Cooling
For your AMC V8 engine, we will suggest the use of our RadLock high-performance conversion radiators, which are rugged, easy to install and are extremely efficient in cooling in even the most demanding environments.
Axles
Use of factory axles is completely acceptable with this conversion. Axle upgrades are not necessary, but they may be chosen for reasons external to this transmission upgrade.
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| A TH350 married up to a 4.0L (Renix era) engine. It offers a tigher, stronger and cooler running transmission than factory options. The 700R4 and TH400 are also great candidates. Note: Renix era engines (1987-1990) require a harmonic balancer-mounted Crank Position Sensor kit, available from sources such as Hesco. |