We report on an analysis of high resolution Chandra spectra of two stars with very similar spectral types and rotation rates but with very different evolutionary histories. AB Doradus is a young relatively bright (V=6.9) rapidly rotating (P=0.51d) late-type star (dK0-2) that is just evolving onto the main sequence. V471 Tau is a post-common envelope pre-cataclysmic binary system and is comprised of a cool main-sequence chromospherically active dwarf (dK2V=9.5) and a degenerate hot white dwarf in an orbit with a separation of only 3.4 R* and P=0.52d. Chandra HETGS spectra of AB Dor and LETGS spectra V471 Tau caught both objects in relatively quiescent non-flaring states and show them to have very similar X-ray spectra. Using a new technique based on the ratios of prominent lines of highly ionized Fe and resonance lines of He-like and H-like ions we have determined the temperature structure and chemical composition of the emitting plasma in both coronae. Both stars have coronae that are relatively Ne-rich and Fe-poor similar to the abundances found from high-resolution spectra of other active stars. We compare and constrast the two coronae in the context of outer atmosphere structure and the rich emerging pattern of coronal abundance anomalies.