Now here's the $64,000 question - with all those 220 backs out there that will shortly become paperweights, it would seem there could be a market for converting them to take 120. But would it be economically feasible? I suspect the level of effort required would be not cost effective - you'd probably have to spend $250-300 in labor per back to convert them, and you could replace them with existing 120 backs for half that price in most cases.