The 2007 Chevrolet Silverado Classic 2500HD LT1 Extended Cab RWD has a standard 6.0 L, 300 hp V8 engine and tows up to 12000 lbs.  This trim has 4 doors, seats 6, and features a 78.7" loading bed.  Think of the LT1 as a midrange trim with an overhead console and power windows.