I suppose one answer is:
As many as is required.
However, as you are building an 8, an easy if mundane way to find out would be to count the pieces Vans shipped to you from the shipping lists.
Do you want to count each and every rivet that will eventually be flying together in close formation?
I would think that the parts count between one "standard" 8 compared to another "standard" 8 may not be exactly the same. A lot depends on how "standard* is defined and of course who the builder is. I believe there is no such animal as a "standard" RV-X.
