I dont trust plastic.Ive run a big Stainless Summit fan in the 440 in my 65 for probaly the last 15 years.No problems.It has a stock never been touched C body rad with a small shroud.I did run it with the stock rad before it went bad.Never overheats and even in the 90s its under 190.My 440 is full race and radical.I run a short spacer as the early bodys didnt have much room between the fan and rad.That and I used to tear rubber mounts easy.Poly mounts now and it dosent move.Rocky