Detailed angular distributions for the 230,232 Th(d, t) 229,231 Th reactions were measured with 17 MeV deuterons, using a magnetic spectrograph to analyze the reaction products. Comparisons with distorted wave Born approximation predictions were used to determine -values and spectroscopic strengths for many levels in both nuclides. These results reconfirm previous assignments for the 3/2 + [631] band in 229 Th, with its bandhead unresolved from the 5/2 + [633] ground state, providing support for the existence of the much-sought "3.5 eV" isomer (for which the latest reported energy is 7.6 ยฑ 0.5 eV). Although 231 Th was previously well studied, many new spin-parity assignments have been made and some changes to adopted model assignments are proposed. There is evidence in both isotopes for appreciable mixing of single-particle orbitals with other configurations, as predicted by the Quasiparticle Phonon Model. Singlenucleon transfer strengths are described much better with earlier values for the Nilsson model parameters ฮบ and ฮผ than later values that have been widely used. An earlier 232 Th(d, t) study concluded that serious errors could result in the commonly-used method of predicting cross sections by combining distorted wave Born approximation calculations using spherical form factors with Nilsson wave functions for a deformed potential, but the present work shows this conclusion is not valid because it was based on inadequate knowledge of the 231 Th nuclear structure.