Nice way to put up the question
Anyways , keep in mind , more the number of parts in a machine whether its reciprocating or rotating , more is the vibration and noise
OHV usually had the cam in their block with rocker arms, push rods and lifters that helped it for valve control
Its an outdated technology as control of valve timing was hectic due to more parts although the engine was compact
That is why they shifted to OHC as the valve is operated almost directly by the cam in this engine and it was easy to obtain the perfect timing - no matter SOHC or DOHC