[0xbadcafebee]

1. Go to Google Flights[1], pick your search options, click Explore

2. On search results[2], find the Departing flight you want

3. On the right-hand side of the flight summary, click the Down arrow ( \/ )

4. In the drop-down description, below each flight leg is the plane description and flight number.

5. Confirm all planes used for legs of both departing and returning flights.

First flight listed:

  Departure:
    SYR to CLT: American Economy  Airbus A320     AA 1739
    CLT to SFO: American Economy  Airbus A321neo  AA 1580

  *Select departure to see return flights*
  
  Return:
    SFO to DFW: American Economy  Airbus A321neo  AA 2504
    DFW to SYR: American Economy  Airbus A320     AA 421

Looking through different options, I can see a United flight that connects from SYR to EWR that uses a Boeing 737 MAX 9 Passenger (UA1513). So I'm not picking that flight.

You can also find plane information at time of purchase, at least from the airline's website. I highly recommend booking direct at the airline's website, as [in the US] by law you have a 24 hour window to cancel your reservation with no cancellation fee.

[1] https://google.com/flights [2] https://www.google.com/travel/flights/search?tfs=CBwQAhoeEgo...