When changing over a rangehood or the corresponding cooktop, you must be sure to comply with current regulation requirements. In Victoria, Australia ESV requires the following clearances:   For gas cooking 650mm minimum clearance from the highest part of the burner of the gas cooktop to the lowest point of the rangehood.   For electric/induction cooking 600mm minimum clearance from the highest part of the electric/induction cooktop to the lowest point of the rangehood. Please see below for the ESV regulations: https://www.energysafe.vic.gov.au/industry-guidance/gas/gas-information-sheets/gis-25-domestic-gas-cooking-appliance-overhead