"blueprinting" is one of those general tems that can mean a lot of different things to a lot of different people. Generally, it means sorting through every part of a motor and making sure it is at the optimal specification. For example, all of the pistons and rods in a blueprinted engine would be the same weight and at the low end of the weight tolerances.
While is it probbaly ture that most exotic car manufacturers build motors to much closer tolerances than a typical production car, few, if any, truely blueprint their motors. I believe the F50 motor is pretty close to that, but I can not think of another example. NSX motors are built to pretty high tolerances and it would be tough to get any significant performance gains just by blueprinting one.
Some exotics, like Lamborghini, have a rep for being very responsive to blueprinting. I once met an English gentleman who was a Lambo collector who told me he got over 50 hp at the wheels on an early Diablo through blueprinting and some very minor head work.
