I can't believe that blue 400 4-speed sold at $21k what a great looking car at a great price. It was right down the road from me too. I guess I'm glad I didn't see it - would have been tempted to have three.
IMHO, try to get a 400 - a clone is okay just don't overpay, and realize it will only go up so much in value. I have a 67 400 vert clone, and a 68 350 2bl coupe - love em both. The coupe is such a great cruiser and very smooth. But the 400 vert turns the heads wherever we show up.
I like the deluxe interior (Comfort weave seats) on the 68s and the wood look counsel, and rectangle side mirrors. I'm also a big fan of the Parchment and Blue interiors, and darker exterior colors. Harolds car is a great example of a beautiful color combination. Good luck - ocaisionally I'll post one for sale on our FB page.
