235's from 54-62 were factory max HP rated at speeds from 3800-4200, depending on the year of the engine. With good rod bearings and good oil pressure, these engines will stay together and produce more HP than most of us will ever need at speeds we're afraid to approach. If an engine is noisy at lower speeds, it's either worn out, or we're just not accustomed to hearing one earning its keep at its HP-rated RPM. The bigger trucks with plenty of gears got run at or near redline pulling max loads or above all day and stayed together.
Jerry
