Would building two cruisers with four twin 8-inch turrets taken from the retired Ibuki help avoid weight problems caused by a measurement-system change?
Short answerNo; the proposal would not solve the weight issue and would leave the ships with an unusual inherited gun installation.
NotesReusing the retired First World War Ibuki's 8-inch guns would not solve the proposed cruisers' weight problem. The brief answer also objects that the resulting ships would have an unusual inherited gun installation. It gives no displacement calculation or alternative design.