Now that we've seen and driven the 2014 Chevrolet Silverado and GMC Sierra, it's time for their SUV cousins to take the stage. We got these spy shots of the 2015 GMC Yukon, Yukon XL Denali, and Chevrolet Tahoe out testing. They’re expected to follow the pickups to the showrooms in a few months. Despite the oval-shaped medallion in the center of the grille, there's no mistaking these testers for anything out of Dearborn.

As you can see, the styling changes are not radical, and all the models will likely be instantly recognizable for what they are, much like the new Silverado and Sierra. And that's probably exactly what GM intended, as it's the sales and satisfaction leader in the full-size SUV segment, and the overwhelming feedback it got from its customers is "don't mess it up." That being the case, the new SUVs are expected to retain a live rear axle, even as the Ford Expedition is going on a decade with independent rear suspension. Although there's a small sacrifice in packaging efficiency sticking with a live axle, the greater durability, reliability, and incrementally better fuel economy afforded by the simpler design likely won the day.

There could be a surprise underhood for the short-wheelbase models, however. There has been a lot of talk about the new 285-hp, 4.3-liter direct-injected Ecotec3 V-6 offered on the Tahoe and short-wheelbase Yukon as a base engine. The Tahoe and Yukon have been offered exclusively with V-8 power since the models debuted in the mid-1990s, but with the new V-6 producing as much power as the 5.3-liter V-8 did in the GMT-800 Tahoe, it's as not as far-fetched a proposition as it might have been a few years ago.

The long-wheelbase Suburban and Yukon XL models are expected to retain standard V-8 power in the form of the 355-hp EcoTec3 5.3-liter V-8, with the 6.2-liter V-8 offered on the higher-trim Denali models. It's unknown whether the Suburban will get a High Country or equivalent trim level like the Silverado. The SUVs are expected to launch with six-speed automatic transmissions like the pickups, but a new eight-speed automatic could appear for improved fuel economy. We could see the final production versions of the SUVs as soon as the Los Angeles auto show this fall.