If you looking for a header to put a muffler on I would look for one that is designed to have one. The 80-82 sohc xs400 mufflers have welded on ones and has an air hole at the top by the head to allow moisture out from the double walled pipe. If you cut them off and put a muffler on it you get an air leak. The 76-77 xs360 and 77-79 xs400 head pipes where designed to have slip on mufflers making it much easier to add a set. Also perform better. I posted pics of the difference in a thread a while back. Do a search of the forum and you may find it.