I too have the 460 with the Banks and the cold air inlet.
We are 38' with tag (22,000#) and a toad (2000#) so I'm not saying that we sprinted up the long climbs on the I15 (San Bernadino and Primm) but we were holding a steady 35-40mph all the way to the top. On the flat she will run 65mph+ until I realize the speed we are doing and have to slow down :)
Unlike the Thorley headers, the Banks system is extremely quiet.
I need to check our MPG when we fill up on Wednesday, but I anticipate around 6.5mpg
I inherited mine from the PO and so am even happier.
