A bit of an involuted response from me here, but here goes. Sorry if this is all a bit space kadett, but it'd confuse you more if I had to simplify it for general consumption!
1. Single out TC/TD 250 Packmaker, Perry or Genie headers were still around in the 80's, but not dual out.
2. I'd sugget you contact FSSP in the US, and ask Mike /Az Coupe/ GT200 nicely to organise a set for you . He showed me a prototype shorty header in 2003 for Fox Mustangs (79 to 81 high mount headers) and they are designed for 2V's and Log heads. Fox Mustangs have a similar engine bay to the Cortina, but with restrictive catalytic converters on a short deck 200 block. Space is therefore limited.
(Mike tried to get some orders, but wasn't certain that there would be a market. Something like 12 000 six cylinder TC to TD Cortinas would be a sizable, bankable market to tool up for. It would allow the common 3.3 US Mustang header to be tooled up, reducing the unit cost).
3. If you do a google internet search on Ford Cortina pictures, you will find a Red 2V TE and a couple of 2V TC's, but the headers on both have been custom made. When you see the picture, then click on enlarge phot, and presto, it takes into the website text and allows you to get info on any new 2V Cortina swaps when they emerge. You've gotta be a bit of a scrutineer to see a 2V, but they are there alright!
The TC rack and pinion steering column joint and the firewall fouls the Falcon headers, while the TE has the radius rods reversed to HZ Hlden style, and these rods get in the way of any dual out header.
Its a fully custom set-up.
The FSPP header possibly fixes that by allowing custom pipes to pass link up with a shorty header, much like the old XU1 GTR Torana/161/186S item only in tubular steel. Daul out shorty headers are the best thing for power and economy in a six becasue they force the owner to look at dual out, low restriction, V8 style exhasts.
4. Oh, and another thing. Cortaina sedan owners with petrol engins can always use the Datsun 180B/200B/240C/260C/280C or Nissan300C fuel tank. They vary from 55 to 65 litres. It sits behind the rear seat like the Holden Gemini item. You then get space for a proper V8 style dual exhast out back, with mufflers as far back in the car as possible, reducing the backpressure by half, and making the car sound nicer.
Spotcha!