The 2005 Chevrolet Silverado 2500HD 4 Dr STD 2WD Extended Cab LB HD has a 6.0 L, 300 hp V8 powertrain with standard 5 speed manual transmission.  This trim has 4 doors, seats 6, and offers standard air conditioning, cd player, and ABS brakes.  Power door locks come as an option.  Max towing capacity comes out to 15700 lbs.