I think this carb would be a little difficult to be fitted by the local ustad's.
According to my poor knowledge.
The port that you circled in blue would be the vacuum port for the distributor timing advance mechanism.
Another port adjacent to airfuel mixture screw would be for brake booster vacuum connection.
Rest 2 ports are for coolant flow to get the auto choke working...
Originally khyber carb has manual choke.
Some expert's may guide you right...
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