Can't answer your question directly, but I will suggest installing Progressive Rear Shocks. They will have a progressively wound spring, which is like having two shocks: one for minor roughness, and a stiffer shock, for more severe roughness, but combined into one single shock absorber. I would also recommend installing Progressive Fork Springs, at the same time, as they balance, and complement each other. The end result, is a very smooth, comfortable ride, with greatly improved traction, as both wheels track much better, with very little time separated from the road surface -- they improve handling dramatically.
Prices vary quite a bit, so find out which model numbers fit your bike, then look around for best prices. Here is the link to the factory web site, where you can dial in your model, to find the Part Numbers you will need:
Progressive - What Fits My Ride.
I do not work for them, or any other M/C company. I am, however, a very satisfied customer/user. I installed fork springs, and shocks, on my '79 CB750K -- loved it, that 30 year old bike rode like it was one year old! I also installed fork springs, and shocks, on my '93 Kawasaki Voyager XII touring machine -- will never ride without this upgrade again, due to comfort, and handling improvements. Search the Internet for independent reviews besides mine. Cheers!
1979 CB750K (sold, 2012, but not forgotten)
1983 Kawasaki 440 LTD Belt Drive (sold, 2011)
1993 Kawasaki Voyager XII