Left goes to secondary vacuum canister (looks like a toilet bowl float). Middle line goes to the tranny. Right line goes to a nipple below the EGR, I think to the intake manifold. I cannot see this connection, but that is where the old one went when I replaced it.
As for the "silver" box on the driver's side fender well, there is a box on it, but it is black. Has some vacuum lines and wires attached to it. I will try to get you a picture of it, but I think it can be seen in one of my earlier picture, maybe on the previous page.
Sorry I totally didn't mean to write it so vague. I have my vacuums run wrong and I know it. I saved your info from the 3 holes in the firewall but what else goes where. I'm a TOTAL noob. I have a carb and air cleaner with lots of screws in hose lol