Outer Limits 4x4 Board

Ok so we got the carby off today and pulled it all to bits. Following the advice of some we took the pre-heat mesh out from under the primary throat in the spacer between the carby and the manifold.
Now the query is, what is with the shroud, block off, peice of tin in the spacer throat under the secondary?
It sits down into the manifold and appears to direct the air/fuel flow towards the front cylinders only. Should I pi$$ it off to acheive better airflow etc? OR does it have a genuine function? IF so what?
Any help etc.
CJ
"Everybody pays for the sins of a couple of morons"

I think that tin guide is spos to face the motor but they wear and come loose which can jam the secondary open a bit . sound like yours has turned around, it is spos to be a tight fit . throw it away. as it can make the motor play up at idle and a bitch to tune.