Weber 36 IDF Fuel Inlet Mod plus Fuel Pump question

Wanting to set up some 36 IDF's for a new motor. Wondering which fuel inlet to block off on each carb, i.e. do I use the big one or the smaller one. The smaller one looks like a similar size to the standard mechanical fuel pump outlet that I would like to use. Will a stock mechanical fuel pump feed both carbs ok?
Any help appreciated

Not sure on which fuel pipe to block,but a correctly set up fuel pump is good for mid13 sec 1/4 mile passes with 48idas.if they are alfa carbs they need some mods i belive,Id always suggest 48idas for any Vw stock 1600s and up

Thanks coletrickle