Mantle heterogeneity has a first-order control of the petrological and geochemical differences of erupted mafic lavas worldwide. Whether this heterogeneity reflects only chemical variability or also lithological differences in source regions is debated. Because of their contrasted partitioning behaviors between mantle phases, First Row Transition Elements (FRTEs) are considered as potential lithological tracers. Using a combination of published data on natural and experimental samples and new high precision analyses (high-current microprobe and LA-ICP-MS analyses), we investigated the various parameters that control FRTE exchange coefficients (Kd) between common mantle minerals and performed inverse modeling to test if FRTE ratios from basalt compositions can be used to solve for modal proportions in their mantle source. We applied the Kd determined from mantle lithologies in this study, along with experimental melt-mineral partitioning coefficients and a simplified batch melting model, on two basalt suites for their contrasted Mn/Fe and Zn/Fe ratios. Our results show that a same FRTE ratio can be explained by a range of modal proportions in the source. However, when combined, FRTE ratios become a powerful tool to constrain the nature of the source.