they are made now in portland,or. I believe.
patricks has them in stock- www.patricksantiquecars.com
$259 a pair. they also have a lot of other speed and nos parts for 235,216 motors. clifforf also makes headers for sixes, but they are tubing, not cast. www.cliffordperformance.com they also have speed and stock parts for all sixes. INLINES FOREVER!