those style carbs have an air door so it wont allow more than I needs. for a very basic slant a small 4 closer to 400 would be better but I think if you tune that eddy properly it will work fine.
in the cylinder head you have the valve seal where the valve closes and seals to keep the cylinder pressure contained, the area just under the valve is known as the "bowl".
what are your plans for this motor/car? daily mpg?