HZ123
For a start BA only have 5xA320-100 (G-BUSB-F). G-BUSG to K are A320-200. All of the above have CFM engines, as opposed to the rest of the fleet which are IAE V2500 equipped.
It is intended that A319's will move to LGW to replace B737's (subject to discussions with BALPA about scheduling rules) as the A321's arrive at LHR from October this year.