Hi Rocky B,
The shock is the right length but you will need to have the top milled to fit inside the 'cup' on the JP2 frame. also the gs shock will have a 14mm,(ish) hole and this will need to be drilled out to take the 18mm(ish)bolt.
apart from that simple task (if your brother in law is an engineer like mine)
it should go straight in. (cant honestly remember if a had to trim the bottom end)
I have a wilbers with remote preload, I use on mine when touring and made the same mods.
one more thing, my shock came off a gs and was far too stiff for the lighter HP2e. it was like riding an ironing board.
I took it to firefox racing and they fitted a new lighter spring and serviced the shok for 100 quid. it came back like new and is perfect.
oh and if you are verticaly challenged, fitting a 10mm spacer to the shock strut while having it re-sprung will lower the seat hight by 30mm.
hope that helps.
