Yes, with a qualification. The Optics Expansion Kit (OEK) (shipping since March 2009) with plastic bases is compatible with Pasco tracks. The parts attach to the side channels in the track. Since the side channel dimension is slightly different on the Pasco track compared to the Vernier track, the fit is not exact, but it is more than sufficient to keep parts stable during an experiment.
The earlier version of the OEK with metal bases is not compatible with Pasco tracks.
Unlike other optics parts, the Diffraction Apparatus (DAK) makes use of the center channel on the Vernier track to firmly attach the translation stage. The Pasco track lacks the center slot.
To use the translation stage on a Pasco track, the stage can be modified by bending two metal tabs out of the way. Rest the stage on the track for use. While this combination will work, we recommend the Vernier track, Combination Track/Optics Bench (TRACK), for the Diffraction Apparatus.