Z20NET Inlet manifold query

TurboCat52

Hello - wonder if anyone can throw some light on the following:
After removing the OE throttle body from a Z20NET inlet manifold you can see an outlet/inlet about 10mm diam below the level of the t/b mounting surface. Once the manifold is removed from the block you can see a corresponding inlet/outlet on the block. Does anybody know what these are for - although they line up visually there is nothing connecting them and they a way apart and I cannot remember removing any sensors etc.?
Any input appreciated.

vocky

I believe you are looking at the engine breather system port dunno..

TurboCat52

I guessed it was something like that but it is just that although the inlet/outlet on the block corresponds with the inlet/outlet below the throttle body mounting surface there is a open space between them and both seem to feed into the manifold.