My dad has fitted a few aftermarket ones to his 4i(4L V8, but NON vented bonnet), tried pacet and another american brand, but within around 18 months same thing on 3 different fans, the magnets on the inside of the motor came unstuck and jammed the motor.
Fitted a Kenlowe, faultless ever since, and shifts a huge amount more air with curved vans.
tabetha