I am flying YVR-YYZ roundtrip in late May and would like to purchase Latitude seats and use a certificate to upgrade into I/J.

Many, many of the YVR-YYZ direct flights show up as being on 767s - five each way each day. Are these necessarily non-XM'ed 767-200s? Or could they be 767-300s (i.e., 763s)?

Also, but on a related note: the daily flight on the 77W is showing J2 C0 I0, but the seatmap shows 24 unassigned seats in the front. Is there any real prospect of being able to upgrade if I shell out for a Latitude fare?