Thanks everybody for your replies. No real surprises, but it gives me an idea of what I can expect if I don't control my impulses to hop up the Barracuda more than carb, intake & exhaust which are my short-term goals for now. It's interesting how some of the modern cars can have such high hp numbers and still routinely knock out mid to high 20's mpg on the highway. I know these aren't light cars but neither are the previous generations of Camaros & Firebirds which I've owned both of and each routinely saw these kind of numbers with real world driving .... I'm not going to totally sacrifice performance either, because the last thing I want is to be spanking by a Ford Taurus or Chevy Malibu!!
Thanks again, Jim