This paper details the development and optimization of a novel seed blanket fuel assembly designed for utilizing high-conversion Th-233U fuel cycles in the current fleet of pressurized water reactor vessels. Previous studies have revealed the necessity to downrate the total power of cores loaded with seed blanket assemblies due to issues with high power density in the seed regions and thermal-hydraulic failure. This new design features solid packing of the blanket region with the objective of increasing the total power and the economic competitiveness. This paper utilized the Serpent code to study the depletion of various designs of the solid blanket assembly, and THERMO is utilized for thermal-hydraulic analysis. A favorable design was developed that attained an excess 1.7% fissile material from the initial loading and that can be run at a maximum power up to 66% greater than the comparable designs used as references in this paper.