you won't need any modifications at all.........but what you will need is to get shot of that 901 and look for a 880 or nippon (something like that) as these are designed to work with the cable routing up from the bottom.
i can't post pictures at work but i'm sure someone will bang one for you
also regarding cable, you'll need to use a rear one (as it's longer) cut it to size and then once you've threaded the cable outer down and through your forks, spray a shed load of WD40 into the top, this will settle in the bend and help keep it running smooth