Built a 408 from a Magnum Platform a few years ago. Recently been running it and dialing in the tune and in doing so making some hard pulls.
It was running really nicely then I noticed a knocking and a wobbly balancer.
Of course I pulled the drain plug and found it full of metal. Pulled the pan and what I found was certainly a surprise. I think tops I am making 425hp with my setup. Its a very mild pump gas low comp build.
Looks like I snapped the crank right after the number 1 main. Brief research suggest this was a common problem for their cast and forged cranks. I suppose its quite thin in this area.
