People tend to get spooky about running stovebolt engines in the power band where they were designed to work well. If an engine is HP rated in the mid-3K RPM range, insisting that it runs at a cruising speed a thousand RPM slower doesn't make good nonsense. Stovebolt crankshafts and connecting rod and main bearings are so over-engineered it's ridiculous, plus the forged crankshafts are tougher than woodpecker lips. With proper bearing clearance and good oil pressure, they will spin happily all day at speeds that would give most stovebolters a case of the screaming meemies.
My daily driver in college in the late 1960's was a 58 Chevy Del Ray coupe with a 235, a 3 speed, and a 3.70 rear axle. It also had 14" wheels. I routinely drove it 150 miles home on weekends at speeds from the mid-60's to the high 70's. It stayed together with no problems.
Jerry
