Integral equations solved by the method of moments (MOM) are an important and computationally intense class of problems in antenna design and other areas of electromagnetics. Particularly when structures become electrically large, MOM solutions become intractable as they lead to large, densely-filled, complex matrices, the solution of which is numerically and computationally intensive. Several numerical techniques have been applied to make these solutions more tractable, notably spatial decomposition and a multigrain method known as reduced current fidelity. This paper investigates the impact of these techniques on parallel computing approaches to solving this class of problem, using networks of workstations (NOWs). The resulting effects on the efficiency and communication patterns of the parallel programs are explored.