I think it's possible, but you would have to swap out most of the roms (all but four of the graphics roms). You would also have to add sockets for the three extra program roms and change the jumpers.
You need a different daughter board but the jumpers do not need to be changed. Some boards have the extra sockets for the extra roms you will need but some don't. I believe it's because of different revision boards possibly.
It's not a rom swap. It is a complete conversion that requires changing out a ton of roms. If you don't want to use the daughterboard and use M27C322 roms, you will need to change the jumpers and PAL as well.
It is a complete rom swap if you do it the way he is asking from his opening post. "Swapping roms" and reburning or burning new roms are 2 different things unless he is wording it wrong in his question.
I was just looking into what needed to be done about taking a grey SSF2 and making it an ST board. Whatever that may be for revision or roms or whatever
dont forget NOTE THAT! if you are using a b-board revision 93646B-3 or a 93646B-4, a modification must be made for an incompatibility, otherwise a sound bug. The trick: If you use a PAL BGSB3G, you must lift pin 9 of PAL and solder a wire on C13 of connector CN3 If you use a PAL BGSB3F, you must lift pin 7 of PAL and solder a wire on C13 of connector CN3