The 8mm shims you seek are probably the ones included in the mini-V wheel packs. BTW, the forum is a much better place to ask questions than facebook. There are 78,000 members here compared to only 6,000 followers on facebook.
Hmm.. so the precision shim im looking for goes cbeam end plate, bearing, SHIM, lock collar. So I assume its the only one that will fit over the leadscrew. Thanks Rick. I guess I should have read farther into the instructions.