It's not suggested to run anything above the stock ride height(lowest setting) on the 5100s with a leveling block installed. 5100s for our truck are adjustable, just not on the fly. They have to be set prior to/during install.
You have 3 options;
- keep your 2" level and install the 5100s at stock height (no preload) this will be the lowest setting on the shocks, and most likely to give you the best ride quality.
- remove the 2" level and install the bilsteins at the highest settings (1.85"), this will be the firmest ride and only net you a small front loss - nothing noticeable.
- disregard bilsteins and other forum members advice, and create a combo for the height you're after (please don't do this)
Alignment is suggested on either option.
Here is a common avenue and forum dealer link - http://www.mrtmotorsports.net/bilstein-shock-sets/bilstein-5100-complete-set/g-82675.aspx
You can also search other places for them, based on these part #'s;
Front : 24-238304
Rear : 33-238319