The 2006 Chevrolet Silverado 2500HD LT3 4dr Crew Cab SB 4WD has a 6.0 L, 300 hp V8 engine with standard 4 speed automatic transmission.  This trim has 4 doors, seats 5, and offers a long list of standard features that include air conditioning, power windows, power door locks, power/leather seats, cd player, and ABS brakes.  Finally, towing capacity maxes out at 15300 lbs.