My Keleo exhaust header failed as well, same jug, but more around the flange where the nut tightens it into the head. IMHO, although it is a cool header, the thing is VERY flimsy. Kelvin told me my break was probably due to vibration, but I doubt it since the prop was balanced and it all ran very smoothly. I'm having my friend (A&P Mechanic) weld it up for me for another go. He's used to welding thin aluminum.