HS6 fuel bowl inlets

["Steve Nabors" <topdown@eudoramail.com>]

I've just gotten a couple of HS6 carbs to put on my TR6.  The fuel bowl has 3 
pipe inlets. The two opposite each other appear to both be fuel inlet pipes and 
then there appears to be a lower vent pipe.  I assume I can use either one of 
the two upper pipes as a fuel inlet and close off the opposite other?  I assume 
two inlet pipes installed to allow for different engine applications?  Can the 
third lower (vent) pipe be closed off as well or does it simply need to remain 
open to the air(or piped/routed back to the air filter)?