The problem with most of those type of books, as well as Ford service manuals, is they are often written by people that had nothing to do with the design, or may have never even looked at the components in question.
In this case, the "lightweight slipper piston" they refer to is a cast hypereutectic piston with a low friction coating on the skirt. And the "forged rods with fracture split lower ends" is actually technically correct, but not complete either. The rods are sinter forged, which means they start out as a mix of powdered metal, and are pressed into a mold for shape, then they are forged with heat and pressure to the final shape as a single piece; then the big end is cracked apart (the forged shape has notches to control the crack locations) to make for a "perfect" mating surface. So, while they are technically forged, they are not what most folks typically think of as forged. Even the Aston Martin 6.0L V12 uses these same powdered metal sinter-forged rods.