As long as you don't have a bunch of loose rod bearings and/or low oil pressure, your 235 will live happily ever after at any RPM below 3K, and it won't self destruct at 3200 for short spurts. Most of the engine noise people obsess about with an old stovebolt when it's wound up is coming from the fan. Just for grins, pull the fan blade off and make a highway run. You'll be amazed at how much less noise you hear, at road speeds you wouldn't even think about running otherwise.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!