With stroker engines, one of the bigger killers is piston rock at bottom-dead-center (BDC). The basic premise is that the piston must still be at full diameter when it reaches BDC even if some of the skirt is hanging out the bottom of the bore. This way the piston won’t wobble and tear itself apart as it’s forced up the bore and past the sharp edges at the bottom of the cylinder. It’s important that the piston skirt is at full diameter at BDC and the necessary taper must be introduced at a point above this. Reducing piston rock also keeps the rings perpendicular to the bore and for better oil control.