Thermoset resin viscosity and permeability of fibrous preforms are important factors to consider when manufacturing a composite part using the vacuum assisted resin transfer molding (VARTM) process. High viscosity combined with low permeability can lead to the manufacturing of a less than desirable composite part. The addition of carbon nanofiber (CNF), to EPON 862 epoxy increased the resin viscosity . The addition of heat and a change in shear rate was also shown to affect resin viscosity . Viscosity differences with a change in temperature or shear rate are modeled using the Lee and Han Equation and the Carreau-Yasuda Model respectively. Using the experimental viscosity data, permeability was calculated. Permeability at higher fiber volume fractions was determined using the Kozeny-Carman Equation; this equation showed that an increase in fiber volume fraction leads to a decrease in permeability. Experimental investigation of resin viscosities at different temperatures and shear rates combined with computer simulation were used to discover the optimum resin viscosity and preform permeability for successful composite manufacturing.