hehe. there's 2 per side.
The instructions I saw didn't say whether to put rtv under them, but the pieces I took out did have rtv on the notched edge - so I put some on there when I replaced them.
I don't think it's leaking unless it's super super slow. I parked over some cardboard let it run for a while, revved it, drove around, no drops that I saw immediately afterward.