Collisions between argon and nitric oxide were studied in crossed supersonic beams. Resonance-enhanced multiphoton ionization was used to determine postcollision relative densities of many rotational, spin-orbit, and A doublet states. A double-beam reference technique was used to compensate for possible saturation in the REMPI probe. A preference for the production of the Pi(A") A doublet component was observed in both final spin-orbit states. Quantum scattering calculations on the potential surfaces of Alexander (J. Chern. Phys. 1993, 99, 7725) agree well with the Lambda doublet propensity but underestimate the observed probability for spin-orbit-changing collisions.