Its been a while since i used mine but the plates are held in place by using the main bore rod and the cam bore rod to determine the orientation of the block in relation to the top guide plate of the tool. It more or less ignores the deck surface. I can’t remember if it bolted to the front of the block. I don’t think it does.

Hope that helps, if not i can dig mine out and snap some pix later this week.

Tony