Vibration is a subjective thing. It is also objectionable (or not) depending on a lot of variables such as baffling, engine mount condition, prop pitch and condition, whether or not something which can transmit sound is touching the engine, whether the firewall sound-blanket is in place, effective, etc. etc.
Even fluid-carrying hoses such as fuel lines can transmit noise/vibration to the firewall (which becomes an amplifying sound-box).
But, assuming a standard prop, the engine's design is not changed just because 5 decades have passed. It's recommended design cruising rpm is 2450, as stated in the documentation. The choice of power setting is, however, the pilot's prerogative. The age of the documentation also does not change the design or recommended operating procedures..
