That updraft carb is a royal PITA. Take a lot of pictures as you go, as the throttle and choke linkage gets a little confusing once it's disconnected. The intake manifold flange nuts have to be backed off evenly a few flats at a time since the area is pretty cramped, and reinstalled the same way. Be sure all the gasket surfaces are very clean, as you definitely don't want to chase a vacuum leak in that area. Take it slow and easy, and you should be OK.
Jerry