hey guys I raced my bf mk1 at calder lastnight on street tires its got about 360+ rwkw on about 18 pounds and at around 5000rpm the rod or rods blew out the side holes about 6inc in radius on one side and a fifty cent piece on the other.....are they common to bust rods I was told they can handle at least 400 450 standard what could have gone wrong??? does the fg bottom end bolt on to the bf head?? no smart ass comments either please