I would never put a modern V8 in a Cobra. At least not one build to replicate the real thing closely.
I want to build a USRRC 289FIA replica, with a Weber fed 289 that happily does 8000. Like Tommy said - its a sound thing
Ofcourse - these things are built for speed and fun, but it must also do some street miles. The occasional drive through town, but mostly highway/backcountry roads and a track event or two.