Over the past two issues I stuffed a supercharged V-8 in an old Army Truck at the Off-Road Connection in Alabama, and in true Southern style it is now time to “let ’er eat!” I started with an ’86 Chevy K30, which was a military version commonly referred to as the 11⁄4-ton CUCV (Commercial Utility Cargo Vehicle) M1008. This truck came with a 6.2L diesel, a TH400 automatic, an NP208 transfer case, and 1-ton axles. With the help of the ORC crew I added a Skyjacker 6-inch lift, 38-inch BFGoodrich tires and wheels from Discount tire, and a front Detroit Locker to match the rear (both axles came with 4.56 gears), and then I yanked out the diesel.
The engine we swapped in is a Chevrolet Performance E-rod LSA, the same engine offered in the top-of-the-line Cadillac CTS-V high performance touring car, but now offered as a 50-state emissions-legal crate engine. This supercharged engine churns out 556 hp and 551 lb-ft of torque. This is four times the horsepower and twice the torque of the 6.2L diesel, and with an aluminum block and heads it is much lighter than the iron-blocked diesel. If you’re wondering why I pulled the diesel to stuff in a gas engine, simply reread the previous sentence.
This month I’ll wrap up the Alabama Army Truck with some safety precautions, some mud whompin’, and a road trip back across America. The truck is pretty well done, but being a gearhead I’m already brainstorming on more upgrades to make it go faster. Stay tuned.
Step By Step
We did a bunch of work and added a fair bit of performance and ability to the truck, so it only made sense to include some safety in the form of a rollcage. It just so happened that the identical model Army Truck of VJ Perrin (Ultimate Adventure 2013 attendee) was at The Off-Road Connection, so we decided to copy his rollcage for faster design.
Wayne Howse fired up the hydraulic Tube Shark tube bender and began forming all the components of the cage for quick assembly. The design uses a rear cab hoop, a front half-halo bar, and front drop A-pillar tubes. Then a dash bar and two crossbars behind the seat were added for support.
For clean assembly we painted all the tubes before welding and then just sanded off the paint where they were burned together. That way we only needed to touch up the paint slightly once in the truck.
The floor was drilled and floor plates bolted to the body. Eventually we will tie matching plates below the floor to the frame, or rock sliders for optimal safety.
Howse covered the seats and dash with welding blankets and the glass with cardboard to protect against welding spatter, and then burned in our new cage. The truck lacks carpet or a headliner, so it was a pretty quick install, and now we’re a bit safer should we get stupid with our newfound horsepower.
What do you do the day after you finish swapping a 550hp engine in your 4x4? You go four-wheeling! We headed over to the Talladega Off Road Mud Track to rip it up. Watch how it did on the Dirt Every Day show (youtu.be/TYh4OAnCW2E).
You may notice the snorkel we added to keep the supercharger from charging our new engine with liquid refreshment. It may not be the prettiest setup, but it is good insurance for wet situations.
Most of the time we wouldn’t be running a mile of flexible rubber hosing to feed fresh air to our LSA. In fact, the normal filtration is an Airaid Cadillac CTS-V intake to a U-Build-It kit that allowed us to plumb the intake over by the fender. Cutting a hole in the fender for the snorkel tube also feeds the air filter fresh cool air as needed.
After my own run in the mud I tossed the keys to The Off-Road Connection’s owner, Keith Bailey, and his daughter to take the truck for a spin. If you look at the smiles on their face you will understand why I tossed the diesel for the supercharged gas engine. This truck is a blast to drive!
A few of our Chevy Performance wiring harness plugs could have been better sealed against hydraulic intrusion (aka water inside). After a bit of wet wheeling the engine started running funny and we had to stop and blow out the plugs. I would recommend better sealing plugs and possibly some dielectric grease to help seal the plugs.
After two weeks at the The Off Road Connection it was finally time to pack up and head home. My new-to-me truck was lighter and faster with its new aluminum engine, but I was getting fatter and slower from all the great Southern BBQ we had for lunch daily. Of course my first stop on the drive home was for lunch!
On Day Two of my drive home I had a small problem. One of the big 50-amp auxiliary fuses in the fuse block for the engine fried. I believe I had overtaxed it by running the electric fans, wipers, headlights, and defroster. Since I had a spare fuse in hand, it was a quick fix on the side of the road, in the rain. Before long I was back to truckin’.
I hit eastern Kansas expecting the notoriously flat state to bore me to death, but found a myriad of dirt roads that crisscrossed the backcountry. Add a pickup with plenty of power and you can make Kansas into an awesome road trip state.
Did you know that Kansas has a town full of gorillas? Neither did I.
Eventually I cleared the Rocky Mountains and found my way to the Mile High Jeep Club’s All-4-Fun event. I showed up a bit late and only got to attend the vendors show on the last day of the weeklong event, but having attended before I can fully recommend it.
This is an awesome family event held in different parts of Colorado each year and has a full spectrum of four-wheeling.
After All-4-Fun I took the Alabama Army Truck over Independence Pass. The truck was running great on this climb, but on others it would suddenly start running hot. I made it all the way home before learning that I had installed the hoses to the BeCool radiator backwards!
It turns out the lower engine hose port is still the intake on the LS engine, even though it houses the thermostat, unlike the older-style GM V-8 engines, which have the thermostat on the outlet. Oddly enough, the new ’14 GM V-8s have the thermostat back on the engine outlet at the top of the engine. Once home I swapped in some off-the-shelf radiator hoses.
However, before I made it home to California I took a side trip to the Grand Canyon. If you’ve never done an engine swap to an old truck and then driven across the country while visiting national parks, I highly recommend it.
Along the drive home I explored as many backroads as possible. With a freshly built 4x4 you’re constantly on high alert for odd sounds, rattles, bangs, or ticks that may portend impending doom. The Autometer gauges kept perfect track of the engine and transmission vitals, and the Army Truck made it home almost trouble-free.
The supercharged LSA may have more power than the old 6.2L diesel, but at 10 mpg it’s not exactly the most fuel-efficient truck, nor is it inexpensive to run since it is recommended to run on premium fuel. Of course, diesel fuel isn’t much cheaper than premium at many pumps.
I rolled back into California via Arizona, and as much as I liked my newfound power, I began dreaming of air conditioning. My quick remedy involved a punctured bag of ice in a mesh laundry bag hanging from the roll bar by the vent window while driving 70 mph across the desert.