Was thinking about how cool it would be if I could get a 69 fastback with the 5.0 and new interior but then it clicked, why not drop a fastback body on a new frame?
Are the dimensions close? Could it work? I know someones done something similar before but I think they just welded old school panels on an 07 gt.
I'm thinking a salvage 2011 GT, cut body off but leave a lot of the pillars and firewall then splice a 69 body on top.
You could do it, but it would be complicated beyond belief, expensive as all hell, and it probably still wouldn't feel like a late model car when finished. You would have to modify just about everything to get it to fit, and it is hard enough getting parts that are intended to fit to fit on these old cars.
That said, I'm a fan of "what if builds," like the kind that you're talking about. I think that the Mercedes that Hot Rods and Custom Stuff built which was a SEMA was freakishly cool. It also cost over half a million. Now a car which wasn't quite as nice could probably be built for half the price, but you get the idea...hybrid builds, as far as I know of are just about one of the most expensive things a person can do.
Several years ago, there was a guy that dropped a '65-'66 fastback body on a 2004 Cobra body. He had to alter all kinds of things just to be able to drop the body on top of the hacked up cobra unibody. It was a really cool concept, and the execution met the level of expectation. However, unless you have a lot of time and money I wouldn't suggest trying it.
Problem is you would end up with a 4000lb 69 mustang. I would think a better solution would be to use a full frome from AME or other and use all the running gear from the '11 mustang. Making it both lighter and faster. Yes modern cars and chassis are nice, but they weight a freak'n ton and have allot fo compromises engineered into them.