Hey Bryan,
I've done this and have a little info to pass on.
Cutting your spacer length down by 1/2" will not lower the front end 1/2". You may have to shorten it by as much as 1" to 2" just to see any difference in ride height.
Of course, using PVC pipe makes this very easy to do.
Shortening the spacer will lighten up the front end's stiffness. Not much but some.
It's a lot easier to just raise the fork tubes in the triple trees your required amount.
