Take the KM DW mechanism off its support. I think it it held by 1 screw? Compare with the hole that holds the proposed new DW tension mechanism. If they are the same size, you can theoretically change them out. If the hole is smaller on the proposed DW, it could be enlarged. I wouldn't bother with this change tho because if you run short when stringing, there is something called bridging. As for calibrating afterwards, it may not be needed because OP wants to change out the entire mechanism. The ratio of external to internal radii does not change, so the KM mechanism should still pull accurately.