I don't drill down to the actual metal of what I flew, cause it messes with the stats for the total miles traveled on the parent airline.
It is simple enough with Alaska to know that flight numbers:
1-999 is Alaska Boeing metal
1000-1999 is Alaska "VX" Airbus metal
2000-2999 is QX (there was a way to tell the difference between Q and E175, but that appears to have gotten thrown out about 6ish months into the E175)
3000-3999 is OO
7xxx is freight and so forth.

Or as others have said, the tail number would also solve the question.