Window Regulator OEM or Aftermarket

[aotte1]

Changing out the original regulator/motor, 1983 K10. Using ACDelco motor along with aftermarket regulator. Also did seal kit from Precision, very nice and easy, fits pretty nice, not NOS, but works good. With change out, window moves up and down nice. However, it moves out of the track when lowered. Tried all the adjustment, no help. Thinking the aftermarket regulator is bad, not keeping window in track/channel.
Question, fix could be a good condition OEM regulator and new AC Delco motor, or a better quality aftermarket regulator, possibly AC Delco regulator. If quality of aftermarket regulators is an issue.