Convert RB67 220 back to 120

I have a 220 back that I'd like to shoot 120 film in. Will the differences in the pressure plate, or anything else, cause problems with 120 film installed? Can I modify it somehow?

I don't really know much about these backs (I don't own an RB); I bought it from a buddy when I dropped it and cracked it.

I'd like to use it to construct a pinhole cam and/or a roll back for a home built 4x5, but 220 film isn't very readily available.

Since 220 film dosn't have a backing sheet the pressure plate setting is different, so will but greater pressure on 120 film which does have a backing sheet. The frame counter gearing must also differ. I think that the simple answer must be to try it and see. I doubt that it can be modified economically.

I've used 120 in my RB 220 for years with no problems at all - it works just fine.