Frankenstein’s Monster: The 8-Second Silverado That Defies Physics


Frankenstein’s Monster: The 8-Second Silverado That Defies Physics


Thanks to his dad’s admirable hot-rodding sensibilities, Brent Wassom’s obsession with big power started at an early age. “When I was a kid, he had this Ford F-100 that he was working on,” he recalls. “One day he says, 'Let’s put the biggest motor we can find in it.’ So we went and got a 500ci Cadillac engine and stuffed it in that Ford. That idea just captivated me – I just thought that was the coolest thing. So, from then on, for me it was just motors, motors, motors.”

The project inspired Wassom to seek out a Cadillac of his own a few years later. After saving up money from his paper route, he purchased a ’64 Deville at the age of 16. But while the Caddy had no shortage of style, the young Wassom quickly learned that big displacement doesn’t always equate to big speed. “It had a 429-cube big block in it, and I thought it was just the coolest car ever. But because it was so heavy, it was slow as could be. So I sold that and got a ’65 Mustang.”

LSFW22 AWD Truck face

After swapping the pony car over to a five-speed manual gearbox and hopping up the 302ci small-block, Wassom had the Mustang running low 14-second ETs at the drag strip – respectable numbers for a teenager gearhead wrenching on a budget. His next project would take things to the next level, though.

”Eventually I sold that one and got a Fox-body Mustang with a T56 and a turbo setup,” he tells us. “That was my first real taste of power. And after that, I was hooked on boost.” Now the owner and operator of Brent’s Automotive in Spanish Fork, Utah, Wassom’s got a pickup project of his own, and the power plant under the hood does the family legacy proud.

LSFW22 AWD Truck Fender Exhaust Detail

“I bought this ’99 Silverado LS Z71 about seven years ago for $800,” he explains. “It was in rough shape from all the off-roading that it had been through, and it I thought a rod was going to come out of the side of the block before I got it back to my shop. But it was straight, rust-free, and had four-wheel drive, and that’s what I was after.”

Wassom soon yanked the tired power plant and gearbox out and replaced them with the 6.0-liter LQ9 V8 and the 4L65-E from a Cadillac Escalade. Outfitted with an LS9 cam, a Precision 7675 turbo and few other good-fast goodies, he estimates that the methanol-fed combination made about 700 horsepower, and that kind of power quickly introduced Wassom to the limitations of factory transmissions.

LSFW22 AWD Truck engine bay and turbo

“The gearbox lasted about two weeks. And that’s when I decided that I needed to learn how to build automatics. I knew was going to be fixing a lot of them.”

The next iteration of project included a 1000-horse turbocharged 408ci stroker LS running on E85, and that level of grunt was enough to send the Silverado into the mid-9-second range at the drag strip. “It was still on stock suspension at that point, and it was getting to be kind of a handful,” he notes. “So we ended up putting a four link in the rear and we put a cage in it, and we also changed the torsion bars up front to a coilover setup.”

LSFW22 AWD Truck rear suspension detail

But the latest version of the Silverado is by far the most potent. These days there’s an LS7-based Dart block under the hood that’s outfitted with a Callies crank and connecting rods, Diamond pistons, All Pro LS7 cylinder heads, and a Holley Hi-Ram intake manifold with a Shearer Fab lid. With a Forced Inductions Garrett-based GTR 98mm/111mm turbocharger running at 28psi, the package puts a healthy 1,650hp to the ground. The power makes its way to all four wheels through a 4L85-E four-speed automatic with a Reid Racing case and bellhousing. The truck still retains its stock front diff and transfer case, while the rear diff has been upgraded to semi-float 14-bolt with a 3.73 ratio.

“The truck is extremely hard on parts,” he says. “But I proudly say that I’ve been in that transmission 18 times – it’s been 18 revisions of that transmission to get it to where it is now.”

LSFW22 AWD Truck Interior

Upgraded tie rods are paired up with the Viking coilovers up front to keep the truck planted and predictable, while the four-link setup in the rear is largely Wassom’s own creation. “We got a generic kit from S&W and just kind of eyeballed it from there,” he says with a laugh. “We had to make a lot of custom brackets for the frame in order to bring the four-link up to it with the right geometry, but it turned out really good. Even with the Viking coilovers, it’s actually more comfortable to drive on the street than it was with the factory leaf spring setup.”

With the 8.50-certified cage, Kirkey racing buckets with RaceQuip harnesses, and an ice tank installed behind the front passenger seat, the Silverado’s interior is decidedly race-oriented. “We’ve still got the stock gauges in the dash, and we’ve also got a 12.3-inch Holley Pro Dash up above, mounted on roll bar,” he notes.

LSFW22 AWD Truck Dashboard Detail

In terms of bodywork, the Silverado now sports hardware from several different Chevy trucks. “I actually just recently put on a hood from a 2007 HD, so now there are no holes in the hood,” he says. “I just didn’t want those big holes in the hood. That’s also one of the benefits of the modular design of the Holley Hi-Ram intake – using that Shearer Fab upper section, I was able to get everything to fit without cutting that new hood up. So now it’s kind of a smash-up of an ’03 front end with an ’07 hood on a ’99 Silverado.” While he considers the look ‘mostly stock,’ we’d wager that the parachute that’s installed out back probably takes this pickup out of contention for sleeper status.

The Silverado has been as quick as 8.82 @ 156 mph in its current configuration – a stunning achievement considering that the truck tips the scales at about 5200 pounds. “When I went into the project, I just wanted to build something fun that was a little different,” he says. “Everybody’s got a Fox body or a Camaro. And I like the prestige of having something that people underestimate. Blowing the doors off of Ferraris and Tesla Plaids never gets old. That’s my ‘different’ – that’s what drives me to do things like this.”

LSFW22 AWD Truck Bed Mounted Radiator

Although the truck doesn’t really fit most race classes, Wassom did get a chance to mix it up in True Street at LS Fest West 2022. “I took second place, next to Cleetus McFarland. I really enjoyed the racing, but parking the truck, walking around, and seeing all the cool stuff was really neat, too. There’s an incredible community around the LS now, and it’s really fun to see all of the wild ideas that people are coming up with.”

As for the build’s current trajectory, Wassom says the Silverado is at a bit of a crossroads. But he also has a clear performance target in his sights. “The goal is to break the certification on the cage. There’s two ways to get there – more power or less weight – but I think lightening it up is probably the best option. If we can take 500 pounds out of this thing, it’ll go considerably faster. But it’s a double-edged sword. I don’t want to do carbon fiber doors and stuff like that; I kind of like that it’s glass and steel right now. This motor could put a Fox-body in the 6s, but I’m not focused on being the fastest guy out there. It’s really more about the cool-factor, and just having fun with it.”

LSFW22 AWD Truck Rear 3/4


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