For all you guys that bought a short shifter either used or the kit didnt come with it, what did you use for the spacer that fills in the excessive space between the end of the shifter bearing and the other side of the [__]?

There should've been washers that came with the kit. If not, just run to Lowes and pick up a few washers to fill in the space and then run the bolt through and tighten...but not real tight.