Assemble the vises, for the final time. You'll not be taking them off again, so tighten everything down, and attach the endplate to the ends of the screw and guide rods. Then mark and drill benchdog holes in the outer jaws inline with the benchdog holes in the top. Generally, through-holes are preferred for benchdogs, so that they don't collect sawdust and gunk. With these vises, that isn't possible, there are screws and guide rods in the way. I drilled them just deep enough to hold a Veritas Bench Pony (their reduced-height benchdog), without it sinking to where I can't get a grip to remove it. Rockler sells some very inexpensive plastic benchdogs that can't be adjusted for height, and aren't as strong as metal or wooden dogs, that I intend to keep in the holes full-time, to keep sawdust from collecting in them.
Grizzly is a company currently undergoing an upheaval. This brand was once known as a manufacturer of professional grade tools and equipment for woodworking products. Though, in recent years, that reputation has begun to slip a bit since being bought by the Chinese company SIEG. These days, whether the Grizzly product stands up to its previous standards of excellence often has more to do with what you are buying than the company itself.