I have no firm knowledge of this, but it does NOT sound like a good idea. It sounds as if it would set up bi metallic corrosion.
Are you wanting to do it to save weight in your race car or because it's one of the few options you have. If it's not a weight issue, I have a radiator guy down here that can do anything and for a reasonable price too.
Are you sure there's not an old fashioned radiator guy in your area that could take care of whatever you need?
Good luck with it.
