C.o.b.r.a

The original Shelby Cobra is my very favourite car.  To me nothing compares to it.  Strictly speaking though it is not an American Muscle car as it is based on an English car, the AC Ace Bristol.
Carol Shelby took the Bristol and along with (I think) Donald Healy and a few others) and put various V8's in them and raced them - very successfully.  The V8's were mostly the 289 and the 427.  They are worth a fortune now and there are are various replicas of them now.  The best one, here in Australia anyway, is the Robnel although unfortunately they are no longer being made