It takes a lot to make a ford Raptor seem demure and rational. This GMC Sierra All Terrain HD does it, though.

This massive GM, set for the stage at the 2011 Detroit Auto Show, features a 6.6-liter 397 horsepower Duramax turbo-diesel V8 with 765 pound-feet of torque. The transmission is a six-speed Allison 1000 unit.

The Sierra All Terrain concept is shorter than a traditional HD Sierra, but features upgraded suspension with three-inches more clearance, a wider — 73 inch — track, front and rear jounce shocks, electronic disconnect stabilizer bars, composite underbody protection, 35" BF Goodrich tires on 20" rims and Fox shocks with remote reservoirs in the wheel liner.

Do we expect this to hit production? No. But this is said to foretell the future styling direction of GMC's truck line. That said, BUILD IT. Ford did…..but Ford didn't include Ram Boxes like GMC has here.