1989 1.8 manifold swap UK redline/webber

[funky]

Hi guys, I am fitting a Redline manifold/webber set up onto a 1989 1.8 Scirocco for a friend.
He has bought the parts from the US and I was concerned about the water port in between inlets ports 3 & 4 as the new manifold l( Redline ) leaves this open to the outside world ( big water leak ).
I have been advised by a so called VW expert not to worry about this hole.
Has anyone out there replaced a 2E2 Solex manifold to a Redline/Webber set up ?

Here is some pics.
We have the set up in the left pic of the haynes manual.
Also here is the manifold off the car showing the o-ring and water port.

Any help is greatly appreciated as I can't seem to get any sense out of the supplyer.

Thanks