My first stop was the local auto wrecker to examine a V-8 installation in a '79 AMC Concord. We had a bit of help here from the factory. AMC installed the 304 in countless Hornets, Concords and Spirits until the 1979 model year. The bad news is that none of the motor mounts, crossmembers or other front end parts will fit in an Eagle, however, I was able to determine the approximate location of the engine.
Next, I pulled the 258 from my Eagle and began to compare the engine compartments. Several problems became apparent immediately. First, the front axle assembly in an Eagle is bolted to the 258. When you pull the motor, you'll be left with the axle on jackstands, Second, in the Concord, the centerline of the transmission/engine is very close to the centerline of the vehicle. In an Eagle, the centerline of the transmission/engine is offset two inches to the passenger's side. Third, the crossmember in the Eagle will interfere with the oil filter on the V-8. Also, the kickdown linkage will not fit in the Eagle. In addition, the lower control arm strut support bracket on the passenger's side is in the way of exhaust components. These are just a few of the problems.
To begin, I pulled a crossmember and frontend assembly from a smashed Eagle, and ''mocked up'' the
entire front end around the V-8 on an engine stand. Piecing the engine and axle mounts together became
a geometric puzzle, going back and forth from the engine stand to the car, working out how everything fit.
The frame rail, strut rod bracket, and upper control arms on the passenger's side aII must be trimmed back
to make enough clearance. I solved the kickdown problem by using a cable to work the throttle valve on
the transmission. To solve the oil filter problem, I used right-angle adapter from Trans-Dapt (Part No. 1420),
and a remote filter mount. This setup has worked fine for over 10,000 miles and the engine seems happy.
THE HARD PARTS
Enough bad news-how about some good news? I used many factory parts to complete this project to beef up the rest of the powertrain (see below sidebar). Many of the parts needed for this conversion come from a V-8 Concord and/or a J-truck. The rear axle was a chance find, I was scouring the wreckers for an XJ Dana 35 (non-C-clip version ) when I found a Dana 44 instead. The counter man complained, "I sent that bloody axle out three times and it keeps coming back. They keep saying it's not the right one.'' I went outside for a look, and there was a Wagoneer Dana 44 strapped to a pallet. My heart skipped a beat. I asked the guy ''How much?'' He says, "Usually I get $895 for Jeep axles-make me an offer." I offered him $400, and he took it. Any Wagoneer axle will bolt into an Eagle. Also, you can find a Dana 44 in some Comanches but the spring mounts are on the wrong side of the axle. The stock Dana 30 was fortified with a TrueTrac diff and aftermarket 3.73:1 gear set to match the Dana 44. The correct gear set is the same as for a Jeep CJ Dana 30, which offers many available ratios.
My transfer case of choice was an NP 219, which has the same viscous-coupling drive system as the
stock Eagle NP 119 to allow full-time four-wheel drive on payment. Additionally, there are Hi-Lock,
Neutral, Low-range and Low-Lock position on the shifter, and the physical dimensions of this case are
nearly identical to the NP 119. It looks to me as if one in a stock Eagle will fit fine behind the 998, as
well. An NP 208 from a Jeep truck will also work, although a longer rear driveshaft will be 'necessary.
An NP 231 may also be feasible, though I didn't try it, (There is a convenient flat spot under the driver's
seat in an Eagle, exactly where the shifter needs to go.) It's my belief these cars were originally designed
to accommodate a two-speed transfer case.
KEEPlNG IT LEGAL
So how does it all work together? The Eagle drives, rides and handles better than the day I bought it. I built the 360 engine for maximum torque in the 1,000- to 3,000rpm range, exactly what this vehicle needed to really bring it to life. Off highway, the biggest improvement is the addition of the low range, next to the added torque of the V-8 itself. With the drikeshafts locked and the wheelspin controlled by the limited-slips, l can go anywhere I need to go.
The installation looks stock because I used so many underhood parts from the '79 Concord. The Holley
Pro-jection works very well; I use the closed-loop option with the oxygen sensor in the tailpipe to keep
How clean? The vehicle passes strict emissions testing (Canada has some of the world's toughest). This vehicle is fortunately exempt from the loaded chassis dyne test because it's full-time four- wheel drive, but still has to pass stiffer tests. The tailpipe reading for hydrocarbons was 112 ppm (300ppm allowable), for carbon monoxide 1.92 per-cent (3.5 allowable). This is without a catalytic converter. (My objective was to build the engine to run clean enough to pass without them.) I believe this swap would be entirely legal in most U.S. states, as long as a completely intact AMC 360 from a later-model Wagoneer is used with all emissions equipment retained.
If there was any demand, I could easily duplicate the engine mounts and front axle mounts. The pieces are quite simple. The hard part was figuring it out; I must have spent 250 hours crawling around before the engine started for the first time.
So there you have it. Not a project for the beginner, but entirely possible for a good mechanic. What's next? How does a 401 with Holler Digital Pro-jection 4 sound? I think the vehicle is ready for a bit more power now that I have the bugs worked out of the swap.