3D integration promises to resolve many of the heat and die size limitations of 2D integrated circuits. A critical step in the design of 3D many-cores and MPSOCs is the layout of their 3D network-on-chip (NoC). In this paper, we explore and present multiple 3D layouts of the Spidergon-Donut (SD) NoC and estimate their longest wire lengths and cost requirements. For a total of 64 cores, the 4x2x8 and 2x4x8 placements result in the best longest wire delays, with the former higher 3D integration costs, while the second requiring larger chip area and through-silicon-vias (TSV) array costs. Such study helps in guiding 3D integration direction and weighing 3D NoC layout and placement alternatives.