The 2500-series models have truck tires and a heavier suspension using leaf springs. The SLE 2WD 2500 ($39,585), SLE 4WD 2500 ($42,385) and the SLT 2WD 2500 ($40,380) and 4WD SLT 2500 ($43,180) come with a 352-hp version of the 6.0-liter V8 that makes 383 pound-feet of torque. Also, 2500 models get a six-speed automatic for 2008.

Also offered are the luxurious 2WD Denali ($48,130) and AWD Denali ($51,175). The Denali's all-wheel-drive system lacks low-range gearing. The Denali models come with a 6.2-liter V8 that produces 380 horsepower and 417 pound-feet of torque along with a six-speed automatic transmission with manual mode and GMC's AutoRide active electronic suspension.

They all have a Tow/Haul mode, which reduces upshifting and downshifting, and also shifts quicker, so the transmission doesn't work so hard when pulling a big load. Transmission oil temperature is part of the instrumentation (along with a tire-pressure monitor).

The SLE standard equipment includes cruise control; three-zone manual climate control; AM/FM/CD/MP3, eight-speaker stereo with XM satellite radio; OnStar assistance with one year subscription; driver information center; the usual powered features, with the outside mirrors heated and foldable; a six-way power driver's seat; leather-wrapped, tilt steering wheel with audio controls; cloth upholstery; auto-dimming rearview mirror; 40/20/40 split front bench seat; six-way power driver's seat; 60/40 split folding second-row bench seat; two-passenger third-row split folding seat; automatic headlights; roof rails; side steps; locking rear differential; three power outlets; and P265/70R17 all-season tires on bright aluminum wheels. Also standard is a tow package with a heavy hitch, seven-pin wiring harness, two-inch receiver and electric brake control harness. A 3SB package for SLE ($835) adds front bucket seats, a power front passenger seat, a front center console, rear radio and climate controls, and fog lights. A Convenience Package ($560) has rear park assist, power-adjustable pedals and remote engine starting.

SLT models get tri-zone automatic climate control with rear controls, front tow hooks, leather upholstery, front bucket seats with six-way power adjustment, front center console, six-disc CD changer, rear seat audio controls and outputs, universal garage door opener, fog lights, remote engine starting, power adjustable pedals, rear park assist, and polished alloy wheels. A 4SB option package for SLT ($3,705) adds heated, 12-way adjustable front seats with lumbar adjustment; memory for the driver's seat and mirrors; Bose nine-speaker audio system with subwoofer; roof rack; and power-folding exterior mirrors with integrated turn signals, driver's side auto-dimming, and reverse tilting.

Denali models come fully loaded, with a wood and leather-wrapped steering wheel; second-row bucket seats; heated first- and second-row seats; 12-way adjustable front seats with lumbar adjustment; memory for the driver's seat and mirrors; power-folding second-row seats; removable three-passenger split-folding third-row seat; power-folding exterior mirrors with integrated turn signals, driver's side auto-dimming and reverse tilting; rain-sensing wipers with heated washers; power rear liftgate; roof rack, AutoRide suspension with adjustable shock settings and rear load-leveling; digital 10-speaker Premium Bose Centerpoint Surround Sound System; and P265/65R18 all-season tires on polished alloy wheels.

An available Sun, Entertainment and Destinations Package ($3,790) includes a DVD-based navigation system, rear DVD entertainment system with 8-inch display and two sets of wireless headphones, rearview camera system, and a sunroof. Other options include remote starting ($175), three-passenger third-row seat ($100), a navigation system ($2,250), rear DVD entertainment system ($1,295), sunroof ($995), power retractable side steps ($1,095), Bose nine-speaker audio system with subwoofer ($495), second-row bucket seats ($490), power release for those seats ($425), power liftgate ($400), rearview camera ($250), AutoRide Suspension ($1,120) with adjustable shocks and rear auto leveling, and 20-inch polished aluminum wheels ($1,795).

Safety equipment on all models includes dual frontal airbags, head-protecting curtain side airbags, four-wheel-disc anti-lock brakes with electronic proportioning, and StabiliTrak, GM's electronic stability program with anti-rollover mitigation and traction control. Options include rear park assist and a rearview camera. The XL earned the maximum five stars in the government's head-on crash tests.