I have a Built small block Corvette that I run at Autocross, and high speed track events. I wraped my hedders over 7 years ago and they have never shown any signs of rust. Wet the material 1st it is alot easier.
I did not wrap the hedder on the SVT, I did wrap the C.A.I. tube, and it is cool to the touch, prior in the summer I could not touch the tube.