Imagine spending more than $100,000 to build a truck, especially a truck from the ’90s.—and that’s starting with a nice, low-mileage one. That just seems wrong, doesn’t it? That’s the world we live in now, however. In an era where a show-quality paintjob can cost $100,000, having a running, driving car for that same amount is a much better choice, especially if it’s one of these two Chevys built by Justin Keith, owner of Killer Performance in Kansas City, Missouri.
While they may look relatively innocuous, you’d be sadly mistaken if you dismissed either one as just a lowered pickup with big wheels. You’d most likely be inhaling a cloud of tire smoke after getting absolutely destroyed by one of these pickups at the track or on the street. Lurking beneath the mostly stock exterior of each of these pickups is the potent heart of a modern muscle car. The teal truck is called the ZL1500 and has an LT4 engine and 10L90-E transmission swap. The red one is called ZR1500. It ups the ante with a modified LT5 and the same transmission. They each ride on ultra-modern coilover suspension, and both have braking systems that would make supercars from just a few years ago jealous. They combine the best of modern GM muscle with the undeniable good-looks of GM’s 1988-1998 pickups.
Performance and Style
There are many reasons why these trucks are so popular right now, but chief among them is that they are plentiful, (relatively) inexpensive, replacement parts are widely available, and restoration parts are even made for them now. Plus, they’re just so good-looking compared to the generations of full-size pickups that succeeded them. That last statement is my opinion, of course, but the surge of interest in these models bears that out. That surge of interest has not gone unnoticed by the aftermarket, and there is a giant catalog of performance parts designed for these trucks that is only growing.
Justin Keith is a savvy businessman who recognized the potential of late-model performance work. After working as a service writer at a Chevrolet dealership for several years, he started Killer Performance with co-owner Curtis Smith. The two operate out of a facility near Kansas City and focus on big performance builds on cars from 2010 and later. But then Justin decided to build an OBS.
Recognizing a Market
Perhaps the move was a stroke of luck, but we suspect he’s good at reading the tea leaves. The Old Body Style Chevy pickups are hot, and Justin recognized a burgeoning market. “Growing up, my grandpa always had a regular-cab ’90s truck,” he says. He started building the teal 1993 C1500 in December 2021, after buying it from the original owner with just 54,000 miles on the odometer. He and technician Steven Prody transformed it into what you see here in about two months’ time. It was far more than just a drivetrain swap, though; this was technically a frame-off restoration. They removed the cab and bed, then completely stripped the frame. Local shop KA Powder sandblasted and powdercoated the frame. It was on this refurbished foundation that the build happened in earnest.
The list of parts reads like a who’s-who of aftermarket performance: the suspension is from QA1; Wilwood brakes were sourced from Little Shop Mfg, of Lawrenceburg, Tennessee; Weld Wheels; Dakota Digital; Aeromotive; and Nitto round out the collection. Justin used the engine and transmission out of his personal 2019 Camaro ZL1. Motor mounts from Elevated Concepts mate the LT4 to the ’93’s frame, and Elevated Concepts also manufactures the frame-stiffening pieces that double as a transmission mount. Genesis Powder Coating gets kudos for treating these various brackets as well as the engine and accessory parts they installed. The big Wilwood brakes were bolted on next, followed by the wheels and tires, and the chassis was quickly a roller.
Justin and Steven then began the meticulous work of plumbing and wiring, utilizing a harness from Speartech. More than just a harness, the kit comes with a gas pedal, and GM ECM, TCM, and fuel pump control module. The ECM comes preloaded with parameters close enough to get the engine running and get them to a tuning shop to work out the final details. They used headers from Speed Engineering, an Elevated Concepts rack-and-pinion steering conversion, a radiator from a 454SS pickup, a Drive Junky accessory drive, and electric fans from LMC Truck. Cordes Performance Racing makes a supercharger expansion tank for C7 Corvettes that fit perfectly on the driver-side wheelwell, and they plumbed it to the heat exchanger they grabbed from Justin’s Camaro. Steven dismantled the stock wiring harness to extract the components needed for the fuel gauge and to keep lights and various other dashboard switches working correctly. The Dakota Digital VHX series gauge panel reads data from the ECM via a CAN-BUS connection and therefore saves a lot of extraneous wiring. Plus, it adds a modern touch to the funky ’90s dashboard.
Proof of Concept
In a short time, the teal truck was a runner again, and before long it was strapped to the chassis dyno at Just Tune in Grain Valley, Missouri, where Justin Kalwei optimized the bits and bytes inside the factory ECM. At the track, the teal truck has run a best time of 10.56 at 138 mph on 20-inch wheels with Nitto 555 R2 tires, not the optimal combo for drag racing. Justin thinks he could dip into the 9s with a better launch on a suitable 15-inch rear wheel-and-tire package.
The red truck came about because Justin wanted to implement the lessons he had learned while building the first truck, saying “We decided to take the teal truck build and go over the top. To do everything that we would have changed on the teal truck build—just basically go one step further.”
The red 1994 C1500 was also a one-owner truck with very low miles—just a touch over 55,000 showing on the odometer. Justin says the original owner had a camper shell installed over the bed and never put anything in there. “The bed was immaculate, absolutely perfect,” he says.
The formula for the red truck is almost the same as the teal truck, with the major difference being the LT5 engine. Not content with his modified LT4’s measly 800 hp, Justin opted for a brand-new LT5 crate engine and 10L90-E transmission purchased through Gandrud Chevrolet. From the factory, the 6.2-liter LT5 is rated at 755 hp, but Justin changed the cam and supercharger pulleys before even dropping the engine and transmission combo in place.
Like before, he and Steve completely stripped the truck to its bare frame. After powdercoating, they installed QA1’s Level 3 suspension, which utilizes a true coilover shock on the front. It requires cutting a large hole in the frame over the spring pocket area. That way, you can mount a long-travel spring and shock assembly, different from the setup installed on the teal truck. Though it seems like a minor difference, Justin says the change in ride quality between the two is striking, and that’s quite a compliment considering how much he likes the way the teal truck drives. The same massive Wilwood brakes, packaged by Little Shop Mfg, are on the ZR1500, but they incorporated Wilwood’s new forged spindles for the GMT400 pickups instead of having to cut the ears off the stock-style spindles.
LT5 Horsepower Boost
Under the hood is where the biggest differences between the two trucks can be found. Though both engines share the same displacement, and both are supercharged, the LT5 has a bigger supercharger and different intercooler plumbing lines. It also utilizes a dry-sump oiling system, so you’ll find an oil tank in the place where the battery should be. Again, they used Elevated Concepts engine and transmission mounts and rack-and-pinion steering conversion, Speartech’s complete wiring kit, and Cordes Performance Racing’s supercharger expansion tank, and their Corvette cold air intake, which was modified to fit the truck. Both pickups still have their stock 10-bolt rear axles, believe it or not. Each one, however, was treated to a complete rebuild and fitted with Yukon heavy-duty axleshafts, an Eaton Detroit Truetrac differential, and 3.08:1 Yukon gears. So far, Justin says they are both holding up just fine. Another set of 20-inch Weld wheels and Nitto 555 R2 tires round out the ZR1500, and Justin said they completed it in even less time than the teal ZL1500.
Finished less than a week before our photo shoot, Justin hasn’t yet had the ZR1500 to the dragstrip. He did spend an afternoon on Just Tune’s chassis dyno, where they saw a reading of 874 hp at the wheel with pulls made in fifth gear, which probably generates a lower reading than what the truck is actually putting to the ground—most dyno pulls are made in whatever gear has a 1:1 ratio. In the 10L90-E, that would be seventh gear, but the wheel speed would be so high that the guys were concerned about driveshaft critical speed being an issue. For now, it’s sufficient to know that the red truck is sending at least 850 hp to the wheels, and all the while, it drives like a new Camaro. “You can beat on this thing at the track, then drive it home afterward without any worries,” he says.
Do you need to spend $100,000 on a 90’s-era Chevy pickup to have this kind of performance? Of course not, but consider these builds as a benchmark—something to aspire to. You can have plenty of fun with a used 6.0-liter engine in an OBS Chevy. For even bigger grins, throw a Magnuson supercharger on top if you can swing it. Either way, you should invest in one of the various 4/6-inch drop kits available for these pickups, and a brake upgrade is also highly recommended, because the stock system is pretty lame. The point is that this is an affordable platform to build over time, as your budget permits. If you stick with it, you could have a pickup as nice as one of these. Both the ZL1500 and ZR1500 represent the potential of the GMT400 pickup as a performance car platform, and we admire the quality of the work done by Justin and his crew at Killer Performance. By the way, KC Detailing deserves major recognition for massaging the original paint on both these pickups to a finish as nice as some award-winning show cars we’ve seen lately. Justin says they are miracle-workers.
If you like these builds, be sure to check out Justin’s YouTube channel Stangkilr Productions. There, he documents each build in exhaustive detail, and that’s a good thing. Tune in, get inspired, then build a muscle truck of your own.
Watch a Full Episode of Roadkill! The Muscle Truck Returns
It had been a while since David Freiburger and Mike Finnegan last saw the original Chevy C10 Muscle Truck and, in true Roadkill fashion, it’s junk and needs fixing! Plus the guys want to add twin turbos to the LS3 in the Muscle Boat! Want to see more? Sign up to MotorTrend+ for a free trial today and start watching every episode of Roadkill!