once you tighten it, that gap disappears... it was the same thing on my centerforce dual friction as with my marlin clutch i have now
EDIT: make sure the dowels are lined up correctly or you will be left with the pp not seated, i had to experiment with mine, the dowels do not fit in universally, there is a spot where all the bolt holes and dowels line up right, they dont just go on anywhere.... once all is lined up, there is still a small gap until you tighten it down