headers for an 87 351?

I have a 87 c.v. with the 351 police package. The previous owner installed true dual flowmaster exhaust system from the cat back. However I am thinking of gutting the cats and getting headers, however I can not find any that will work on a c.v. Anyone know where I can find some? Also anyone know of any other inexpensive (less then a couple hundred $) power mods?