REX HP is producing headers for the passenger cars, I bought them ceramic coated for my 56. Price is a little rough $690 and $195 for ceramic plating plus the shipping, but they are true 4 tube, 1 5/8 primarys, 2 1/2 exits. I should get them in a couple weeks, I'm just an end user with need for parts, Gord McMillan at REX is a wealth of Y-block info and he seems to enjoy sharing it, that's the way Y people are. I been waiting for headers for a while, and figured better now than maybe never. That pic is from an email he sent and they are obviously not coated.

Ted, Redding, CA