I put the magnesium single sided replacement 999 arm on a 998 which is for all intense and purposes is the same thing you're asking. Yes it can be done. I made an adapter plug for the swing arm that relocates the lower shock mount above the swingarm duplicating the lower position of the stock 998 swing arm. I also made a longer adjuster rod. I think there was also some minor bushing or adapter changes. You may have a problem with the exhaust which I didn't have.