Thank you for the response. I'm just really confused. My searches have pointed in the same direction. I got the AC Delco struts off rockauto and even on other sites they come up as police/taxi for a 2010 Impala. I'm starting to worry someone put the wrong strut in the right box. I needed to loosen the sway bar end link to drop the control arm a little to get the knuckle bolt holes lined up with the strut. I understand the 9c1 struts ride a little higher, but should the fully extended length have been any different?
I'm not sure what the next step should be. I can think of several things to try, but they may also be a waste of time
One thing that may be simple is to do a side-by-side comparison. Were the new struts complete with springs and mounts? Or did you have to assemble them by moving the spring and mounts over from the old ones?
If you can take just the strut cores and lay them next to each other, how do they compare? Are they the same length? Are the lower spring mounts in the same positions? With the rods pulled out all the way, how do they compare?
As for having to remove the sway bar link, I can't recall whether I needed to do that or not, but probably did. In fact, I might have also put a pry bar on the control arm to bend it down to get the bottom strut hole lined up with the hole in the steering knuckle.
One of the upsides to going to a parts store, and, I will add, a sort of tradition, is that you can lay the old and new parts side-by-side on the counter for comparison.
If you decide to pursue some more police type struts, and you can find them at a local outlet, take your old one with you for a comparison.
If you find police struts but they're again too tall, you can then fall back to regular stock struts, and put this to rest - for sure, this sort exercise can be frustrating.