B&M 360 balanced flexpate?

I was told to install a 360 in place of my 318 in my 72 dart, that I needed a B&M balanced flex plate. I ordered a SFI rated 360w/904 flex plate from jegs and got it in today. I cant figure out what I got. I take it the flex plates are not the same as ferd or cheby. this one has no ring gear or teeth. how do you install thing thing? there is nothing on the crank of the 360, so do I just mount it like I would a 350 flexplate, and then mount to tranny? where are the ring gear teeth for the starter? are they attached to the torque converter? sorry for the newbie question, but when I ordered it I thought I would get more :lol: