If you've spent the $$$ on a carb, a turbo isn't going to work in this configuration. I mean, you 'can' do a blow through but it is really limited to what kind of boost you can run and it is a sketchy way to turbo an engine. Just don't - this is an opinion only and there are 'right' ways to turbo an engine. Off the top of my head it's 5/16" fuel hose for the main fuel feed. Return lines are 1/4". You can block off the return line but do not block off vapour/breather lines. It can cause vapour lock in the fuel system which will cause the engine to starve out of fuel. Check the Weber install threads to guide you through the upgrade. There is a list of things you should do while mounting the Weber (mostly manifold mods for the coolant lines/barbs as the coolant feed will be redundant and can cause hidden issues if not sealed off properly)