It was easy to over rev those engines. The L78 had domed pistons and an over reved engine would float those valves and bend those push rods. It did happen to me once.The issue with the 396 was the push rods bending. My uncle was a mechanic at a chevy dealership. That was his only complaint on the 396. I drove his Chevelle a couple of times, and your right. It was fast.