I also had a couple reproduction Hi Po fans let go. I have a 65 GT fastback with the factory "K" engine. I basically only use the car for MCA shows, so I rarely have the engine above 5500 RPM, but still had the same experience as you. Since this car needs to be original, I searched for an original Ford fan that would work. By searching junkyards, I found out that the fan from an early 69-71 Maverick, 200 C.I. with factory air, has a fan that is the same as the Hi PO, except it is 1/2 inch smaller in diameter. I have used this fan for the past three or four show seasons, without any problems with overheating, and not one judge has ever questioned it. (maybe now they will)