340 'Tuned cast iron exhaust headers' any photos or details?

Hi guys, I was talking to a guy & Carlisle & he said he had a set & had only seen two other sets.

He bought his set over 30 years ago.

Does anyone here have any photos of a set and / or know who made them?

Be neat to see, I've never heard of them.

I haven't either, but I have heard of many Ghost Hi Po parts

Last one I saw turned out to be the usual 1968-71 (best) factory iron; "I was told they were tuned".

May be confusing the D dart headers, not sure if they were cast iron though and they were for the 273. Nope they were Doug’s headers