>From what I understand, the upgraded speedos are basically "plug and play", meaning you don't have to swap out anything but the gauge. I've never dug into the binnacle, so I don't know what's involved in replacing a guage. Contact any vendor for more information. Don at DMC Garden Grove set me up with my 160 speedo and I haven't had any problems. Give him a call and ask about the options. 714-554-6794 -Christian