Aluminum and magnesium castings reinforced with Fiber FP, Du Pont's alumina fiber, are being developed for high-performance automotive applications. The connecting rod has been selected as the model to assess the value of these reinforced castings and to develop design and fabrication technology. While they are lighter and may offer better compressive strength and stiffness and fatigue resistance than conventional engine materials, their design still representa a major technical challenge. A comparative study was undertaken to predict the structural behavior of connecting rods using two- and three-dimensional finite element stress analysis models, and to determine the most cost effective modeling and analysis approach. Results from all the analyses match closely and correlate well with static and fatigue testing of FP/Aluminum and FP/Magnesium cast connecting rods. We discovered a useful alloy composition. casting conditions, and machining techniques. And we identified computerized industrial tomography as a reliable method of determining casting quality.