Well, i had to remove the tap assembly from the tank as i was using a different carb setup and needed the clearance, so had a couple of pipes (about 3" long) welded into the lobes each side, its a fiddle, not a lot of clearance so you need to get the positioning spot on, i then ran a pipe from each via an inline filter (as the filter had been part of the tap assembly i'd dospensed with) one to the main supply on the side tap the other to the reserve input.... this works well, only drawback is that you don't actually have an 'off' so rely on the tap working well, i've been running like this for 6 years no problem.
you can either fabricate a blanking plate for the old tap hole or, as i did, weld it up.
good luck