I'd see if you can tap it out for a 3/8" NPT pipe plugs (or 1/4 NPT if small enough). Make sure if you don't have a spread bore carburetor that you get the metal plate to "square" the intake openning for a standard square bore carb (like edelbrock performer series carbs or holley standard carbs). You can find one here: http://www.summitracing.com/parts/EDL-2732/
This will ensure you don't have a vacuum leak from the channels on the bottom of the carburetor
You could always go with a phenolic spacer or the like as an alternate option to keep heat out of the carb too
Just make sure it also seals properly
As for the EGR block off, if it just has a couple holes you may be able to tap/plug those as well. Worst case you can take a 1/4" plate of aluminum, a hack saw, and a file and a drill and "make" a block off plate with some elbow grease
One other thing! Any pipe plugs you put in that may have atomized fuel going past it (i.e. bottom of runners under carb) make sure to use a type 2 gasket sealer on the threads as it will harden and not become gummy or soft when exposed to fuel (like teflon tape can). Should be a brown color and most auto parts stores carry it in the RTV section in a smaller tube.