These are on my 91flhtc. They are at the longest shock adjustment. If I move it will the ride be stiffer or softer? Never messed with anything like this. They are 13" and I'm assuming moving the notch will preload? If so wouldn't it ride even stiffer?

 

The shorter step is the softer ride. The taller step compresses the spring more than the shorter, so more firm.

 

The shocks in the picture are set at minimum pre-load, longest length, softest ride, most likely to bottom out if you add significant load weight, such as a passenger. All that said....if you add pre-load the ride you experience will be more stiff but if you also add a passenger...they will be less likely to bottom out.
Hope this helps.

 

Thanks, that's what I was thinking but didn't want to hear. These things are stiff as a board. I'm hoping maybe another 1000 miles may change that. When I ride 2 up I haven't changed a thing and that is when it seems the most comfortable. Just super stiff solo.