Cylinder Head/Flange/Headers Question

Don't headers have any kind of casting number? I looked yesterday and I can't find anything anywhere. I guess a look at the ports would give me an idea. Well right now I just want to find a gasket that fits without making one. I'm going to yank these drag headers off for some TTI's or Hookers? Does anybody know about fitment? TTI sounds like they spent a lot of time to route around steering, starter and other equipment, where Hooker doesn't really mention. Man this stuff is way more confusing than I thought. I thought building a master bath was hard this is a total pain, but definately more rewarding :)