Cylinder boring question

That is correct.

A .030" groove in one side, will be required to be bored out .060"
to clean it up.

Put a center-line through the top of the cylinder, and if it is bored out,
.030" will be removed from each side.

my duster has been bored .060 and it runs okay--it will run a little hotter than normal--mine runs about 195 even in hot weather--would recommend a good radiator--as far as holding up i've had the car 14 years and have not been into the bottom half yet--of course it's strictly a street machine--no racing---good luck