And I seem to remember reading that Goku was around 5"9' and Gohan was 5"11'. Is there really only supposed to be a centimeter of difference?
Well, if you look at group pics or pay extra close attention to when Goku is next to Gohan, they are actually basically the exact same height. Gohan might be marginally taller, but it isn't an inch. It's maybe 1/8"