Ousted AMC V-8
I have an ’81 CJ-7 with a carbureted AMC 360 in it. It has a Ford T-18 manual transmission, Dana 300 transfer case, and Dynatrac axles front and rear. It rolls on 37-inch Boggers and is beat on regularly. The AMC 360 is finally tired. I looked into rebuilding it for 400 hp, but the cost is kind of ridiculous for this Jeep. The AMC motor always had plenty of torque, but it was gutless. Also, pretty much all of the accessories on the front of the engine are worn out. At this point, I’m kind of done with the AMC engine and I’m not a Jeep purist. A friend is practically giving away a complete Chevy 350 V-8 with all of the accessories. How viable is this swap, and what parts would you use? Dustin Ewing
The AMC V-8s are well known for having an incredible amount of off-idle torque, making them great off-road engines, especially at slow speeds. AMC V-8s are also well known for being significantly more expensive to rebuild and hop up than the more common GM V-8. Having said all that, an engine rebuild is almost always less expensive than an engine swap, but it’s not always more practical, especially in the long haul over several decades. In your case, you can purchase a stock rebuilt AMC 360 long-block from companies such as ATK (atkvege.com) for around $2,700. A comparable GM 350 long-block is about $1,000 less. Given that it sounds like you have your hands on a complete, inexpensive GM engine in good shape and that you already have your mind made up, you should sell the complete and still-running AMC 360 to recoup some of the costs of your GM V-8 swap. There are likely plenty of Jeep purists around looking for a good AMC 360 core to rebuild. Good cores are not plentiful, and new engines have not been manufactured in more than 25 years.
It’s fortunate that you have the Ford T-18. This is probably one of the most adaptable manual transmissions available. It can be easily married to most popular engines and transfer cases. However, the Jeep version of the T-18 was available with many different length input shafts, several of which are completely unusable when doing an engine swap in a short-wheelbase Jeep. Advance Adapters (advanceadapters.com) offers a 360-degree bellhousing kit that will mate the GM 350 to your Ford T-18 (part number 712549). The kit includes a bellhousing, dust cover plate, GM release lever, GM throwout lever spring clip, ball pivot, pilot bushing, and the necessary hardware. This aluminum bellhousing is also drilled for the ’77-’79 Jeep T-18 transmissions that have a 2-inch-long pilot tip. A high-profile GM 11-inch diaphragm-type clutch assembly is recommended for this bellhousing. Centerforce (centerforce.com) part number CF165552 works well. The included ball pivot and clutch release arm are designed for a location that is limited to only the high-diaphragm–type clutch. This larger 11-inch clutch assembly will require the use of the 168-tooth GM flywheel. Ford
T-18 input shafts are normally 11⁄16 -inch diameter with 10 splines, which will require the use of a Centerforce clutch disc (part number 281226) or equivalent. A Centerforce throwout bearing (part number N1714) finishes out the clutch assembly. Your stock CJ-7 slave cylinder and bracket can be retained and adapted to the new bellhousing and GM clutch release arm.
Advance Adapters offers both weld-in (part number 713007) and bolt-in (part
number 713089) adjustable motor mounts for your CJ-7. The weld-in mounts are generally a better choice for a Jeep that is used hard off-road. Both mount styles feature massive 5⁄8 -inch through bolts with isolators that will pretty much put an end to rubber motor mount failures.
Novak Conversions (novak-adapt.com) takes a different approach when adapting the Ford T-18 to a GM V-8. The company retains the GM bellhousing and mates it to the Ford transmission with a few simple and cost-saving modifications. This gives you the ability to use most GM bellhousings, including full-circle or open-bottom types. Novak Conversions also offers adjustable weld-in motor mounts to secure your GM engine to the Jeep CJ frame.
As for cooling, you’ll need a new radiator with the proper inlet and outlet locations. Fortunately, the popularity of the CJ-7 has led to the availability of numerous aftermarket radiators with GM V-8 inlets and outlets. Bolt-in GM V-8 conversion radiators are available from companies such as Advance Adapters, Champion Cooling (championcooling.com), Summit Racing (summitracing.com), Radiator Express (radiatorexpress.com), and many others.
You may be able to keep the transmission and transfer case where they are currently located, which will simplify your engine swap and reduce costs by not requiring driveshaft modifications. The key areas to make sure you have enough clearance will be between the rear-mounted GM distributor and the firewall, as well as around the engine, exhaust, and accessory group clearance near the factory CJ-7 steering shaft. If space is limited or there is contact between the components, you’ll have to evaluate the options of modifying these areas or simply move the transmission and transfer case to accommodate them.