I am not sure as I am trying to get the details now. I know the Ofna 16mm kits come with multiple rod ends so you can use a smaller end, but not sure on the total length dimension. The guys supossedly running them are in the Georgia area, so I am trying to get details through email. 16mm would be a huge increase in oil volume though as it is a 13.8% increase in area alone without subtracting the shaft diameter, which would take up even more % of a 15mm shock. I estimate the volume increase to be over 15%. Can't you simply limit the droop with the droop screws? I would also think some fuel tubing cut to length could be used inside the shock under the piston as well to lower travel?