Would anyone know a place that sales header for a 240 six so you can put dual exhaust on it. ?

 

Clifford performance

 

Clifford performance has them but kind of pricey. The efi manifolds are a good way to go and inexpensive. You can find them in junkyards or ebay like here: http://cgi.ebay.com/ebaymotors/NEW-8...Q5fAccessories. , though that set is too expensive. They frequently can be found for about 25.00 a set.
Doug Thorley made them at one time but not sure if they have them any more. I know because I have a set in my building that I've never used.

 

Use 87 to 96 fuel injection exhaust manifolds from a 4.9/30CI six. They flow extremely well and give true dual exhaust. Can be had in a junk yard for 10 25 bucks.

Garbz