Eagle 3.58" cast crank, who's broke 'em ?

Never broke a 4", but was leery enough to sto pusing them. I've got two 4" ones in use - between 450-480hp on both, one going on 9 years in service and 20K on it. I'd think as long as it's internally balanced and the mains are align honed(all engines I do are) you should be fine for anything under 500hp. That's just my opinion tho. I haven't heard of any 3.58s breaking but they may also be a service replacement rather than "performance" part.