The prospects of Optical Burst Switching (OBS) as a cost-effective optical networking paradigm depend both on the complexity of the network nodes deployed and on the network performance attained. Contention resolution devices, namely wavelength converters and Fibre Delay Line (FDL) buffers, and the size of the optical space switch matrix determine, to a large extent, the complexity of the core nodes. Consequently, the cost-effectiveness of an OBS network can be improved by deploying only a small number of converters and buffers. Moreover, the use of strategies that minimize in advance the probability of contention can assist in the task of further reducing the number of these devices. This paper evaluates the loss performance of an OBS network based on shared wavelength converters and FDL buffers and using wavelength contention minimization at the ingress nodes in order to gain insight on the dimensioning of the core nodes that leads to an improved network performance.