I've always wondered if I would have the same passion about a Cobra had Shelby been able to cut a deal with GM and use their small block? I suspect it would have lost a TON of appeal for me. I go to the local cruise in's and the car lot is FILLED to overflowing with 350 crate motors ad nauseum! What a thrill to see an old flat head, Pontiac or Olds engine under the hood, like it was 'back in the day'. But for a real thrill, it sure is nice to stumble onto a genuine FE on rare occasion (and THAT includes COBRAS, by the way)!
Do something different, stuff a Hemi in it if you don't care for the FE.