While checking the valves on my 470 I noticed that the ti pipe is now in contact with the radiator and has caused some pitting in the radiator. There was also a little coolant on the pipe and surrounding area and I do not believe that the leak is coming from some where else (ie I believe it is coming from the point in contact with the pipe). Is it possible to weld the hole and space off the header? What material is the radiator? Origninally the header was in contact with the unabiker radiator guards, but I trimmed down the support (as you can see in the picture below) to clear the pipe. . . unfortunately the radiator then came in contact with the pipe. Any ideas on the best way to proceed from here?