Think of it this way, If Chevrolet had the technology to build the trucks with the suspension, drivetrain, ect... they would have. Why drive something that is uncomfortable or lacks the horsepower that you can have with a more modern engine? Paying homage do the style of the vehicle while updating it is simply a way of keeping these vehicles relevant and practical.
They had the technology back then, the cars all had independant suspensions in front. They elected to build a truck like a truck. They aren't cars they are TRUCKS. If you look at any real truck that is brand new off the line today you will see the same frame and suspension features that the older 50's pickups and larger trucks had in the day. And there is nothing uncomfortable about them, cept bias ply flat spots.
As far as power? Unless your pulling a 14k pound trailer there is plenty of power, yes the rear gears need a jump up in ratio for more speed and brakes need an upgrade in the master cylinder area, thats about it.
