The Department of Defense, through the Naval Supply Systems Command (NAVSUP) Weapon Systems Support, is seeking proposals for the repair and modification of a heat exchanger, specifically NSN 7R-1660-016004921-V2, with a quantity of five units required. This procurement is critical as the item is flight essential, necessitating government source approval prior to contract award, and only previously approved sources will be considered for this solicitation. Interested vendors must provide comprehensive technical data and documentation as outlined in the NAVSUP Source Approval Information Brochures, and failure to submit the required information will result in disqualification from the award process. For inquiries, potential bidders can contact Allen Neyland at (215) 697-4314 or via email at ALLEN.NEYLAND@NAVY.MIL.