Jon Thomas has a unique automotive advantage that many gearheads covet deeply. The Georgia-based performance fanatic punches the clock every day as one of the R&D new product development technicians for Competition Clutch. As you can imagine, this position has opened some huge bay doors for the guy and his 1999 Chevy Silverado.
What started with fixing a funky Jeep CJ7 at the age 15 years old quickly turned into a job turning wrenches at Firestone to make ends meet when he was 16. But as he learned his way around the shop and how to change things like tires, oil, spark plugs, plug wires, and other forms of routine maintenance, Jon Thomas realized his career calling in life was purely automotive in nature.
Photos by: Wes Taylor
From there, it was on to Universal Technical Institute, where Jon earned a degree in automotive technology. Ultimately, this education led to a job with Porsche’s graduate program in Charlotte, North Carolina, where he worked for Hendrick Porsche. Again, Jon found himself tackling everything from oil changes to installing performance upgrades on customer cars for upcoming track day events.
During this time with Porsche, Jon married his high school sweetheart, Jessie, and shortly after getting married, moved back to the couple’s hometown to work at a local hot rod shop. Restoration, performance, and repairs consumed Jon’s life from that point forward, with carbureted cars from the 1950s to 1980s being his primary focus. A transition to the dealership world brought work as a technician and, eventually, a shop foreman role that would last upwards of 15 years.
The Race Bug Always Bites Twice
Jon began to build and race cars and trucks in the middle of that, starting with a 1988 GMC 1500 4×4 with a small-block 400 that he converted to a carburetor setup. Mated to a rebuilt transmission and a 14-bolt rearend and accompanied by a long list of other mods, Jon’s truck began to make the rounds at local car shows and meets.
His love for GM trucks officially in full bloom, Jon traded the 1500 pickup for a 1991 Chevrolet step-side two-wheel-drive with a built small-block and a T-56 six-speed gearbox. This rig rocked a 9-inch rearend and ladder bars, which gave cause for Jon to begin drag racing, where he consistently ran 12.40s in the quarter-mile.
Eventually, the drag racing bug caused Jon to buy a 1972 Chevrolet Nova, which he raced at tracks in Georgia and Alabama for about eight years. This vehicle allowed Jon to get into the final 16 during the 2008 series of “Pinks All Out” hosted at the Atlanta Dragway.
After all that noise, it was on to a 2001 Chevrolet Tahoe with a supercharged LS motor, which would be traded for the 1999 Chevrolet Silverado 1500 you see here. The truck was running and driving fine, with a hot-rod-black paint job, a mismatched interior, and a turbocharged 6.0-liter motor. Jon proceeded to blow both head gaskets (twice) before sending the transmission to the morgue and reconsidering his life’s decisions.
A Silverado Work Truck Reimagined
But instead of giving up on the chassis, Jon repaired what was broken, converted the Silverado over to a six-speed manual, redid the entire fuel system, and changed up his wheel and tire combination to run the truck at autocross events. The shift toward turning his pickup into an all-around road race, drag race, autocross, school drop-off/pickup, and date night multitool had finally begun, and what would follow would be equal parts extensive and expensive.
Since older GM trucks have never been known for their handling prowess, Jon decided that building the 1500’s footwork foundation around VA Specialties front coilover conversion and tubular control arms would be a fantastic starting point. Eibach 1000-lb. springs and Viking Performance double-adjustable coilovers and QA1 double-adjustable shocks in the rear, with 4-inch drop shackles, and hanger kit cause the rig to sit just right. Removing the overload spring from the leaf springs brought better rebound balance, and Hellwig sway bars both front and rear add the control Jon craves in the corners.
Throwing a Wilwood six-piston 14-inch front brake kit and refreshing the factory GM rear disc brakes brought increased clamping power, supported by a Wilwood triple pedal billet master cylinder assembly with the brand’s inline staging brake setup.
As for the truck’s drag pack setup, Jon’s 1500 sports Weld S77 17×5-inch front and 15×10-inch rear wheels, all encased in Mickey Thompson radial rubber, with the rears rocking 295/65R15. As for the whole autocross and street performance part of the equation, Jon switches to Volk TE37 wheels in a 18×10.5-inch squared configuration, with GT Champiro SX2 295/40R18 tires on all four rollers.
Power comes complimentary of GM’s LS LQ9 base, with a 408 stroker short-block built by Pro 1 Automotive & Machine out of Covington, GA. The shop loaded the truck’s block with a forged crank from Liberty Performance Components, billet I-beam rods from the brand, and CP Carillo forged pistons affixed to create a balanced rotating assembly.
GM 823-casting LS3 heads come loaded with Texas Speed 660 springs and retainers, a valve job from Pro 1, Brian Tooley Racing hardened pushrods and rocker arm trunion upgrade, and Johnson lifters. Induction and fuel delivery come courtesy of a high ram intake and Holley’s signature sniper 102mm throttle body from Holley Performance Products.
These air induction goods are force-fed by a Forced Performance/Precision HD85/88 T6 journal-bearing street turbo controlled via a winning combo of a Precision Turbo 44mm wastegate and a 50mm TiAL blow-off valve. The truck’s boost controller is run through the Holley Dominator ECU, with Trick Performance’s stainless T4 log manifold and 4-inch air-to-air intercooler “taking charge” of the air situation. Custom cold-side piping from LRB Fabrication finishes out the boost side of the build.
As the Holley Dominator EFI setup, tunned by Nate from NTG Tuning, controls the fuel sprayed by Injector Dynamics 1700 XDS injectors, fueling is handled by an Aeromotive 5.0 brushless pump and fuel pressure regulator. There’s also an On3 Performance manifold for handling exhaust waste, which hits a series of clever one-off pipes in the bed, which we will cover shortly.
Gear shifting within the Chevy Silverado begins with a Texas Drivetrain Performance built T56/6060 hybrid with a Corvette gear ratio rated at 1200 lb-ft. This is followed by a Vengeance MPC six-puck ceramic twin-disc unit from Competition Clutch and a 3.5-inch aluminum driveshaft with a Sonnax billet slip yoke.
The power comes to a head at a factory GM 10-bolt packing one of Got Torque Differential LLC’s differential big shaft kits. The unit is complete with billet C-clip eliminators, Dutchman 33-spline axles, and spool, a 3.90 gear from Yukon paired with a 1320 rear disc 15-inch conversion. Added strength comes from a Moser girdled diff cover and Strange Engineering billet yoke. Traction is further increased by a set of Calvert Racing Cal-Trac bars.
The Laguna Pipe
Jon had a basic 3.5-inch turbo-back exhaust exiting in front of the passenger’s rear tire when this build began. Everything was groovy until the day Jon attended the Pro-Touring truck shootout, where the max exhaust level sat squarely at 103-decibels. After failing one sound inspection after another, Jon’s Silverado faced disqualification, as a third violation meant going home. So he slapped a silencer inside the downpipe, which helped him meet the regulatory requirements at the race, but also created a ton of backpressure, which in turn caused his turbo to fail.
Taking his setback as an opportunity for improvement, Jon spent the next few weeks rebuilding his Silverado’s blown turbo and fabricating a stainless 4-inch turbo-back exhaust. Piped straight into the bed and set at an angle, this one-off exhaust’s articulation allows the bed to serve as a sound diffuser with the exhaust’s open port positioned so that it cannot be easily read by a decibel meter. Jon fondly refers to his exhaust as his “Laguna Pipe,” paying tribute to the bonkers exhaust setups required to run at Laguna Seca due to noise ordinance requirements.
With a more free-flowing (yet cleverly muffled) exhaust on deck, Jon received zero sound violations at LS Fest a couple of weeks later. There’s also a quick disconnect section that allows Jon to easily swap in a muffler in place of the “hater pipe” section in the bed, which was only utilized while at LS Fest in the past year.
A Silverado Bed and Cab Built for Putting in Work
In the bed of the Silverado, you’ll find a 20-gallon fuel cell with a small catch can and rollover vent assembly to reduce the risk of running out of go-juice or puking fuel due to sloshing while on an autocross course. You’ll also discover a three-quart Accusump setup triggered by oil pressure to release pressurized oil back into the engine if the oil psi drops too low. Oil starvation and cavitation within the oil pump were the primary reasons why the main bearings failed in the previous motor, so Jon is always sure to check and top off the remote-mount oil filter under the hood so that the oil cooler in the bed stays filled.
Inside, we find a Holley digital dash, Kirkey aluminum racing seats, Racequip five-point harnesses, an ARC four-circuit switch panel, MGW’s original F-body shifter, and a GT Grant suede steering wheel. Cruising and custom car show upgrades include a sound system by Audio Concepts built upon an Iron Ace console and an interior dyed a rich shade of satin black. Although this Silverado came to Jon with a pre-installed roll cage, he tells us it is more of a glorified harness bar. It remains on the shortlist for future modifications since it’s not built to spec or certified for going faster than 9.99 in the quarter-mile.
Once you’re past the Superman conquering custom “Kryptonite” green paint scheme, you’ll come across a carbon-fiber front splitter and custom lower air dam. You will also notice a late-model Monte Carlo rear spoiler from Five Star Bodies, Trackspec Motorsports hood vents off a 1968-72 Chevy truck that have been modified by Level 7 Motorsports. Tow straps were added to the front and rear for race day. Finally, for “drag and drive” style events, Jon has installed a brace to mount a rooftop coffin into the bed to keep the luggage dry and away from prying eyes.
When asked about the insane color on his Silverado, Jon explains that the Kryptonite Green came into existence without his knowledge. At the time, a friend, Greg Butera, was supposed to touch up the door jams so that they would better match the body’s hot-rod-black look. So you can imagine Jon’s shock when a quick video chat update of Greg’s “touch-up job” revealed a rig sporting one of the most intense shades of green south of safety vests and radioactive ooze. While he was indeed quite taken aback by his friend’s tenacity, Jon loved the color. He allowed Greg to paint the intake, turbo, brake calipers, control arms, and door jams so that everything would match.
Onward and Upward
Paint job complete, Jon and his Silverado competed in the first annual pro-touring truck shootout in Kentucky in 2020. This was followed by LS Fest 2020 (blown motor anyone?), with the most recent rebuild leading up to LS Fest 2021 last September. Jon and his Silverado also competed in Street Car Takeover at Atlanta Dragway, where he got runner up in the truck class for drag racing and was told that he now holds the world record for “quickest full-size GM stick shift truck in the quarter-mile.” How quick, you might ask? Try 10.098-seconds at 134.20 mph on for size.
Future goals for this Silverado Wrktrk include taking back the title of “World’s Quickest GM Full-Size Stick Shift Pickup” from a friend who swiped it from Jon this past February. This will be accompanied by some road course action later this year, more drag racing, a dash of drifting, and an appearance at as many events as possible. All while not breaking anything and having as much fun as possible.
But racing isn’t everything, because outside of track sessions, this three-year-long build has done a brilliant job of allowing Jon to enjoy his truck both on and off the track. This bright green pickup does droves of different things exceptionally well, all while working reliably the entire time. This explains how it has earned the nickname and license plate title: “Wrktrk.”
One of the most memorable experiences for Jon and his Silverado was the day he took his son, Reid, on a quick part’s run to Summit Racing. Later that day, they returned home not only with a bunch of goods, but a first-place car show trophy! We told you that Kryptonite Green paint scheme really plays upon people’s weaknesses…