Ron;
John Mummert has a nice set on his website, but as far as I know they are not available yet. Maybe he can update us here with a ballpark date they will be available and a (ballpark) price. Also, Jerry Christenson will make a set for you and he advertises in the Y Block Magazine. I am using a set of Red's Passanger Dual Tube Headers in my 56 Customline that were an easy fit, but I'm sure don't flow as well as Jerry's or John's (when his get on the market. Here's a picture of what the Red's Headers look like.
Rono
Ron Lane, Meridian, ID