A method and incorporated assembly is provided to enhance structural integrity and prevent interface deflection in a computer rack having a midplane and capable of housing a plurality of nodes. The assembly comprises at least one structural filler book capable of being disposed above or below said midplane where any node may be disposed having geometry and material properties to resist and counteract the plugging force of said node an causing a cancellation effect. The filler book have at least two horizontal supports being connected to one another via a vertical support and a plenum an air for directing air flow. The filler book is being secured to said rack or midplane via an engagement component disposed on one of its horizontal supports. The engagement component has a complementary air duct such that when said filler book and said engagement compartment are engaged and disposed in the rack, the air duct and the plenum align to provide a tuned path of air to be delivered to electronic components plugged to said rack and midplane.