They are coated. It is only one tube that is in the way. I would actually consider buying a different set of headers if I knew for sure they would clear the shaft. I could re-sell mine to offset the cost. I do know of a shop that could alter the headers, but not sure of the cost or what to do about re-coatong the area. Scott
I had to use 3 u-joints to clear a big block that was moved way back, though my preference would have been to use 2. I recommend using quality u-joints, keep the u-joint angles as small as possible, use a well mounted carrier bearing as near the center u-joint as possible, and make sure the u-joints are properly phased. In the picture that I have attached, the center support bearing is not installed, but you can see the mounting tab just below and ahead of the center u-joint. Good luck.