Most cook top units are 23 wide x20 deep altogether. There is an overhang underneath where it sits on the worksurface so it is hard to say whether the gap you have would maybe be too big as the gap has to be smaller than the overall size in order to sit properly on the supporting worktop.
I have a 23 inches slap. What would be the ideal dimension of a four burner cook top to fit with it??
