  We analyse the so-called violations of quark-hadron duality in Finite Energy
Sum Rules with the LR correlator, through the study of the possible high-energy
behavior of the LR spectral function, taking into account all known
short-distance constraints and the experimental tau-decay data. In particular
we show that the use of pinched weights allows to determine with high accuracy
the dimension six and eight contributions in the Operator-Product Expansion,
O_6 = (-4.3^{+0.9}_{-0.7}) 10^{-3} GeV^6 and O_8 = (-7.2^{+4.2}_{-5.3}) 10^{-3}
GeV^8.
