Current springs can be adjusted to your liking but will take testing to figure out.
If you cannot get somebody to help u with sag settings just look at the manual, set the bike up to the "standard" setting and go riding on your favorite twisty road. See how the bike feels to you and make SMALL adjustments one at a time.
Make the adjustment, ride, then monitor your feedback....ie, felt good u liked it, did not feel good ..etc.
If you're not good at it be all means used a little notebook to write down the settings, what adjustments u like or do not like and so forth.
If u'r gonna "eyeball" it, I'd say based upon your weight u may have to increase rear pre-load 1 or 2 settings to the "harder" side then ride and fine tune it in.
Also u'r riding style dictates how the suspension will be set. I use very little brakes so my settings may not work well for u.
All in all the stock settings are "very stiff" for 160lb riders....this is a plus for the heavier guys. Ride, see how it feels, write down pluses or minuses, make small adjustments and re-ride the same route. Pretty soon u'll have it dialed in how u like. It just takes alittle time.
Tarl