I've just done exactly this
My pillion is my boy who's slightly shorter than me, but gives him better leg sitting if you know what I mean.
Was just a straight forward swap
you'll be pleased to know.
It drops and pushes forward the rear pegs by, I think, 45mm, not much granted, but still good or better than 98 model. The later models are rubber covered just like riders pegs, although I swapped them as didn't like that 'look' the other thing is the actual seating area is thicker on newer models thus lifting the pillion up a wee bit as well, so you might want to look at a newer seat to give your good lady a better ride
On a continuous thing on the above mod.....
Since I've done this I've noticed more vibration through the handlebars and getting numbness in my fingers with pins and needles. Thinking it might be that I hadn't pushed the exhaust in properly when I changed the rear pegs as it moves that slightly too, when I got home I loosened of the exhaust and pushed it 'home' a bit better, hopefully that'll help but won't know till I go for another run with it like that, unless anyone can shine any light on this?
Original exhaust 98