The "shark fin"-looking front sight blade on those looks, and is, so much taller than the front sight blade on a fixed sight M-60 for 2 reasons. First, the adjustable rear sight sits quite a bit higher than the top of the frame's topstrap, where the fixed rear sight trough and notch is machined, so the front has to be taller.
Second, there is a good bit of upward movement of the muzzle when the shot is fired, even before the bullet leaves the muzzle. This, the muzzle has to be pointing downward a bit so point-of-aim and point-of-impact can be brought together.
Like has been said, the correct sight picture is to line the top of the front sight blade up level with the top of the rear sight blade, while centering the front blade in the rear notch.