[Tim Brewer]

You don't have to fill the whole thing through the manifold, maybe just a top off after the first cycle to posibly displace any air.
Miles, all intakes should have a plug that you can remove to expose the water cavity in them. It's not really a fill hole, but it is a high point that allows you to displace any air if there is air in there. There is also sometimes a plug that goes to the open cavity where fuel and air are drawn in.