Recent experiments have employed the phase sensitive nature of the Josephson effect to determine the wave-vector dependent phase of the gap function in high-temperature superconductors. A parallel combination of Josephson junctions, commonly referred to as a dc SQUID configuration, has been used in many experiments to probe the gap function symmetry via transport measurements. Asymmetries in the junction properties have required various extrapolation procedures to extract symmetry information from measured field-dependent transport measurements. Here we analyze the finite-temperature properties of this system in the experimentally relevant limit of large self-inductance, where the asymmetry is due to a difference in junction critical currents. We derive a scaling relation between systems of different self-inductance, leading to a new extrapolation procedure to determine the gap function symmetry.