The 2027 GMC Sierra and Chevrolet Silverado models are shaping up to be pretty seismic updates for the iconic pickups. The 1500 models are getting new tech and revamped exterior styling. But the one missing piece of the puzzle has been detailed information about the new V8s that will be making their debuts in these rigs, with the company keeping key details close to the vest.

This is now changing, with GM revealing all the details about its new V8s and how it is attempting to rewrite the script for GM in this key category.

New V8s bring more power and refinement to GM

The two new powerplants will cover two different sides of the coin, with the 5.7-liter L76 V8 replacing the outgoing 5.3-liter and the 6.6-liter L78 engine replacing the 6.2-liter. A main selling point here is increased power, with the new 5.7-liter producing 402 horsepower and 428 lb-ft of torque. That’s a sizable gain when compared to the outgoing motor. GM says the displacement was increased thanks to engineers lengthening the stroke of the engine by 6.0 millimeters.

This increase in stroke adds 47 extra horsepower, and the engine also features both port and direct fuel injection. As a bonus, the 5.7-liter can also tow up to 13,700 lbs when the Silverado it’s in is properly equipped (the GMC gets slightly less numbers). Meanwhile, the 6.6-liter V8 is all about performance, and while its 9400 lb tow rating (9300 in the Sierra) is noticeably lower than the smaller engine, it makes up for it by producing 481 hp and 501 lb-ft of torque. That’s 61 more hp than last year, and torque also increases by 41 lb-ft.

New engines may share DNA with Vette engine but are made for truck duty

While the two new V8s are in the same family as the 2027 Chevrolet Corvette’s LS6 engine and share the same bore, they are completely different animals. Instead of being track stars like the LS6, both the 5.7- and 6.6-liter engines are meant to be the best at doing truck stuff, with some of their internal workings being fortified to ensure they survive the rigors of cargo hauling and towing.

GM says the new engines will initially be built at its Engine Operations facility in Flint, Michigan, with the first wave of production being built exclusively at that facility. Later on, GM will use extra production capacity at Tonawanda Propulsion in New York and St. Catharines Propulsion in Canada to boost the supply of engines while also taking pressure off the Flint facility.

The two engines will be making their debut along with the trucks later this year and will be part of a bigger gamble the company is taking on V8s. The move is also getting attention, with Ford recently confiming it’s expanding V8 availability to all F-150 trims starting in 2027.