Hennessey drops 522 kW into the GMC Sierra AT4 and turns it into a Raptor R rival
Texas tuning house Hennessey took the GMC Sierra 1500 AT4, bolted a supercharger to its 6.2 litre V8 and raised output to 700 bhp, or 522 kW. The result is the Goliath 700 Sierra, a pick up that runs from 0 to 97 km/h in 4.2 seconds and pushes General Motors’ luxury truck into territory where the Ford F 150 Raptor R has so far made most of the noise.
GMC left a gap, Hennessey filled it with force
According to Hennessey, the Goliath 700 Sierra uses the AT4 as its base and adds a twin screw supercharger, a water to air intercooler and HPE engine management calibration to the 6.2 litre petrol V8. Power rises from 420 bhp to 700 bhp, or from around 313 kW to 522 kW. Torque climbs from 624 Nm to 828 Nm.
This is not a gentle software tweak. Hennessey increases output by 66 per cent and moves the Sierra AT4 into very different company. A standard 6.2 litre Sierra is already a strong, comfortable and quick American full size pick up. The Goliath 700 turns the same platform into something that can worry a sporty SUV on tarmac and shift its own mass with surprising violence on gravel.
0 to 97 km/h in 4.2 seconds is serious pace for a pick up
Hennessey quotes 0 to 60 mph in 4.2 seconds, which translates to 0 to 97 km/h. In a full size truck, that figure would have belonged to fast sports saloons not very long ago. The Goliath does not pretend to be a track car, but its supercharged V8 gives it the instant response and muscular mid range punch that large off road tyres usually do their best to blunt.
The Ford comparison shows exactly where Hennessey wants this truck to sit. The 2026 Ford F 150 Raptor R uses a 5.2 litre supercharged V8 producing 720 bhp and 868 Nm. That is about 537 kW, so the Goliath 700 falls just short on power, although the gap in torque is hardly vast.
The Ram 1500 RHO heads in another direction. Its 3.0 litre twin turbo Hurricane straight six makes 540 bhp and 706 Nm. Ram has the argument of a more modern powertrain and a factory warranty, while Hennessey answers with old school V8 character and a lot more power.
The chassis gets more than just a taller stance
The Goliath 700 package does not stop in the engine bay. Hennessey adds BDS suspension, upper control arms, Multimatic DSSV dampers, 508 mm off road wheels and 889 mm off road tyres. That matters, because a 522 kW pick up without proper chassis work would be little more than a straight line tyre smoking machine.
The AT4 makes a sensible starting point. GMC offers the 2026 Sierra 1500 AT4 with four wheel drive, a short or standard length bed and a factory 51 mm lift. Ground clearance reaches 282 mm on the short bed version and 279 mm on the standard bed model.
Hennessey also fits steel front and rear bumpers, underbody protection, a 1016 mm LED light bar and a set of 76 mm LED lights. The carbon fibre bonnet insert is not merely theatre either, since Hennessey says the functional vent improves engine bay cooling.
Exotic in Europe, but not pointless
From a European perspective, the Goliath 700 lives in a very narrow niche. The GMC Sierra 1500 is not an official mainstream model here, and its size, emissions and fuel use make it more of a special interest toy than a rational everyday vehicle. Even so, projects like this explain why the American full size pick up remains so resilient at home. One platform can become a work truck, a luxury vehicle, an off road machine and an absurdly quick V8 entertainment device.
In Europe, the Goliath has no direct rival. The Volkswagen Amarok and Ford Ranger Raptor play in a smaller, less powerful class, while the Mercedes AMG G 63 costs more and carries a different luxury SUV image. The Hennessey Sierra is rougher, louder and less rational, but also more honest. It does not pretend to be a frugal tool for every occasion.
Hennessey sells more than a power figure
The value of the Goliath 700 lies in the complete package. It includes a stainless steel cat back exhaust, black exhaust tips, Hennessey and Goliath badges, powered side steps, all weather floor mats, embroidered headrests and numbered cabin plaques. Each truck goes through dyno tuning and road testing, while Hennessey provides a limited warranty of three years or 36,000 miles, roughly 57,900 km.
That matters because the buyer of a 522 kW pick up does not only want a large engine. They want a story, a sound, an attitude and some reassurance that the thing can actually be used. The Hennessey Goliath 700 Sierra plays exactly that role. It turns the GMC Sierra AT4 into the model General Motors itself has not quite dared to send after the Ford Raptor R.
Technical summary
Base model: GMC Sierra 1500 AT4 with a 6.2 litre V8 and four wheel drive.
Power: 700 bhp, or 522 kW, instead of the standard model’s 420 bhp, or 313 kW.
Torque: 828 Nm instead of the standard model’s 624 Nm.
Acceleration: 0 to 97 km/h in 4.2 seconds.
Chassis: BDS suspension, Multimatic DSSV dampers, 508 mm wheels and 889 mm off road tyres.
