Weber Marine Carb on 360 la engine?

If the MVA port is blocked & you don't want to drill it.....
You can use the large port, bottom centre, carb rear. This is also MVA; usually used for vac to the brake booster. If used for the booster, you can put a Tee fitting in the line. If no booster, & there is a plug there, you can a fitting to take 3/16" hose.