I wish I would have seen this thread sooner!
82F100SWB: I did the same number cruncher a couple months ago, and I agree with you wholeheatedly!!!
Personally I have done a junkyard twin-turbo setup on a fuel injected 351w Mustang. Flipped the manifolds, and it was sweetness.
If I had the time I'd be all over a twin 6.9 setup. Myself, I'd fabricate the manifolds from scratch with pieces from the plumbing store. They have nice steel 90* and tee pieces in various sizes, with the edges beveled for easy welding. Piece of of 1/8" steel flatbar bolt to the head, cut out holes for the exhaust ports, and do the plumbing!
Just like this:
http://sdsefi.com/techheader.htm
I made my own turbo flanges quite easily for my twin Mustang project. I brazed in fittings to the oil pan so the turbo oil could return. I'd do the same for the IDI.
A twin IDI would just look so clean, with true dual exhaust and stacks... mmm...
