Rowdy 1,200-HP '70 Duramax-Powered 4WD GMC K15 Race Truck Is a Work of Time and Heart

Disclaimer: trailers and support vehicles have no place in this smog-ridden, gas-drenched competition. And sadly, this is no hang-out for clientele or race car fanatics with chunky pockets and zero experience with a wrench.

It's the kind of event that tickles the ego of the most qualified mechanics, tuners, and hands-on enthusiasts. After all, what's good in a car if you can't race it on the strip and enjoy it in the streets?

After setting their average times at the drag strip, racers hit the public roads onto the next race venue – it's a sight to behold on the freeway.

Javier of That Racing Channel on YouTube got to experience the rawness of 2023 Sick Week and showcased some of the most brutal builds of the competition. Among them was an impressive 1,200 hp (1,217 ps) four-wheel-drive diesel truck with an attitude. As usual, we couldn't help but share some of the event's automotive niceness.
Like most cars in the battle arena chasing speed, this brutal diesel truck has a story. According to the owner and builder, Wyatt, the racer is a 1970 GMC K15 truck that's had a long history in the family (bought new) for more than five decades.

After years of serving as a workhorse in the family, it, unfortunately, got in an accident. However, Wyatt wasn't ready to turn it over to the crushers. At this point, it began its new chapter as a race truck.

"It originally started out like, oh, I just want a fun weekend truck, you know, nothing too crazy, and three years later, it's finally done, and we've built a monster," Wyatt spilled the beans on his race truck's history.

This truck wouldn't earn the title 'monster' if it were a make-believe boogeyman hiding under a six-year-old's bed. Thanks to the potent powerplant it runs under its 53-year-old exterior, it deserves every title it owns.

Anytime two automakers join forces to enhance performance, history is made. And as such, Wyatt's 1970 GMC K15 beast of truck runs a Duramax LB7 powerplant, the General Motors and Isuzu Motors partnership ingenuity.
He cut his perfectly running daily driver, a 2003 Chevrolet Duramax, into half and put the K15 body over it. The result was a full tubular back half, four-wheel-drive Duramax-powered race truck.

Ideally, the only thing left on the race truck that is part of the original Duramax is the front frame rail, engine, and front suspension setup. According to Wyatt, he kept the front half of the Duramax because he wanted to keep the four-wheel-drive layout. Also, GM didn’t hold back when developing the front geometry of the Duramax – a bonus for this kind of build.

It wouldn't stand a chance against the competition if it were a bolt-on build. To maximize performance, he included a couple of mods; big injectors from XG Performance, a GM 4L80-E transmission to handle all that power, four-wheel-drive capability, and a massive turbo for that extra kick.

It's dynoed at 890 hp (902 ps) but makes up to 1,200 hp (1,217 ps) when the nitrous kit is put into the equation.

"It is crazy with a different feeling, you know. You don't have the RPM and the horsepower that some of the gas guys do. But the torque? It'll get you, and it hooks you," Wyatt confessed about his build.

Javier also checked out a BoostedBoiz & PFI Speed tuned big turbo AWD Honda Civic. We recommend catching some of that feisty action and more in the video below.