The owners manual for my 74 CB550 has a fork oil replacement section. In which, it states to refill with 5.4~5.6 oz. (160~166cc).
In section 13 of the Honda shop manual, under cb550 specifications, It states that the Front fork oil capacity 6.3~6.5 oz. (185~191cc).
You do use less for a refill than for a dry assembly, as you can't really get all the old oil out from the drain plug.