Yours is the 2nd thread I've read lately concerning oil leaks. I think they come in 3s. - Or is that celebrity deaths?
The intake MRL installed on my 408 had similar plugs. I tried to remove a few that interfered with my throttle cable mount and couldn't get them out. I ended up just grinding them down. I would imagine that any of yours that are leaking might be removable with more effort. It sounds like a pain in the butt but I'd pull the intake off if you can't get the plugs out otherwise.
