I used a new set of header gaskets. They say you don't need to but It just didn't seem right not to have a gasket there.
Forum: Dodge Sweptline Truck General Discussion

Not sure if this will help. Try Sandersonheaders.com I got a pair of shorty block huggers for my 70 D200 fit like a glove. I have a auto trans with 2 wheel drive but Sanderson's claim is that their headers are tested on the application that they are puchased for. They have 3/8ths inch thick flanges and have a guarantee that they won't leak. Mine didn't.
Forum: Dodge Sweptline Truck General Discussion