It can use a variety of engines. I'm not sure if it can handle a V12, but the LSx isn't the only V8 available. RCR built one with a twin turbo Lexus V8.
http://www.autoblog.com/2011/08/15/hennessey-venom-gt-to-make-official-u-s-debut-at-monterey/ Hennessey has announced that it will show off its Venom GT on Wednesday, August 17, 2011 at the McCall's Motorworks Revival during the Pebble Beach weekend, which will take place at the Monterey Jet Center. Of course, we've seen various images of the car along with a few videos thrown in for good measure, but the Texas-based company says this is the car's first official unveiling in the U.S. after making an appearance at the Goodwood Festival of Speed in the UK. In any case, who are we to shun an invitation to gaze upon the glorious Venom GT? With 1,200 horsepower, a 0-60 time of 2.5 seconds and a top speed estimated at 267 miles per hour, this is one supercar that we're more than happy to drool over. See the first car delivered to a customer in our attached high-res image gallery, and click past the break for a brief press release.
Does a european designed and built car become American when a fat scam artist drops an obscene engine into it? Oh yeah, shelby cobra / ford GT40 / etc .. I forgot!
and yet the reverse happins in europe maserati bi-tubro steals the beautiful and classic american chrysler car JSUT BECAUSE it had some shitty italien engine in it!!