No specific advice about these shocks, but on most bikes a 1" rise in the rear results in about 1° decrease in rake. Less rake = more twitch, but the stock setup is so conservative you could take out a lot of rake and still have a rideable bike. I'd also be concerned about more flex & stiction in the forks under braking, though.
FWIW, it's not particularly hard or expensive to get the correct-fitting shocks & springs painted to suit your bike.