The 891's will settle a smudge, maybe 1/4"...especially depending on the loads you carry. I assume you got 891's because you load it up often.
For the front, you can use some top out spacers with the 883's, however:
-A 1" spacer will give you nearly 1.5" of lift. A 1/4" spacer will give you about 1/2" of lift.
-If you are going to wheel it, using top out spacers in the front is a real good way to tear up your CV's. Because you effectively lengthen the shock, and you get more droop than the CV's can handle. I don't think you're going to wheel it hardcore though, based on your geographic location. Like me.