Just an FYI: The 300ZX OEM stainless steel header gasket 20691-01P80 can be used if you need a good new primary to secondary gasket on a header. Here's the catch: the bolt holes do not line up and you will need to drill / cut / cuss / throw it against the wall to make it work. :D
Really, if you have a Dremel I'm guessing it should be pretty easy to modify.
If you're working with a drill and a set of wire cutters, expect it to take about 2 hours of your time.....

I used a dremel on mine, and it look a long time. Maybe I had the wrong stone. I used a round file on the gasket for my wife's car, and it cut through the gasket like a hot knife in butter.