noob needs help with mileage - only 10 MPG!

The carburetor overhaul should do the trick. The hallmark of a carb running over (Bad/clogged needle and seat, or sunk float) is the engine running well when cold, (when it needs a richer mixture) and having trouble idling once warm. Also, pulling your plugs you'll find they're dark or even black with soot.

I tell people who have trouble like this, to take off the air cleaner, start the engine, open the choke, and look straight down the carb with a flashlight, if anything is wet, that is the problem. If everything is still dry, have someone cut the car off while you're looking down the carb. if it's running over, fuel will drip from the boosters onto the throttle plates.

In either case your problem is either a bad needle and seat, trash in the needle and seat, Your float may have gone bad, may not be adjusted properly, or it may be excessive fuel pressure (No carb should ever be fed over 5psi of fuel pressure, and hi-po and electric fuel pumps are good at doing that. you'll want a regulator if this is the case.) Regardless, a carb rebuild is in order, and that should fix the problem.