check out where they are connected to(runner or waterport) I'm pretty sure that they are both constant vaccum for a tree or brake booster. I can't realy remember tho cuz i don't realy pay attention after everything is hooked and working.
On my Performer, one is vaccume and the other is water. I have the vaccume pluged and I have a water temp gauge in the other. Hope this helps
BTW, nice looking f/b. Is it painted the factory silver blue or an other similar color?