I installed, by myself, a set of Sumo Springs Bump stop replacements on my Chevy Express 4500 based Freelander front and rear. As you noted, it did increase the ride height in the front...for me about 1/2 to 3/4".
The rears were not as noticeably higher...they just sat on the axle at about the same height as before. On the Chevy, the factory rear bump stops did not touch. The Chevy factory fronts did touch all the time although not compressed.
What a difference..right out of the box. Not sure I need another alignment but the next short trip should tell.
Not hard to install if you have a capable jack and jack stands....or a mechanic friend who lives next door like I do. :)