Quite a few years ago, I had a red 79 Camaro. Yeah, I know... it was a squeaky, rattling, trailer-park-lurking GM product. But it was my first car, and it was actually in excellent condition, and it was FAST!!!
Anyway, my father and I had built an impressive 383 small-block for the car, and it would easily maintain 140mph on a long, flat stretch of highway.
However, the aerodynamics of the car were NOT designed for such speeds, so as I recall it was pretty "floaty"... If I had welded some 18" wings on the doors to add just a bit more lift, the thing probably would have flown! Hahaha...
I also had a friend who had a black 72 Corvette with a juiced 427 in it... I did over 150 in that car a couple of times.
I was quite envious of it.
I'm not a NASCAR fan at all... but I got to drive the #6 car on the Talladega track last year, and maintained ~170mph for a few laps.
It was quite fun, but intimidating too.
Mike