3.23 or 3.55?

Pretty car! What color is the interior??

I have 323's in my 69 Dart automatic with the 14" tires and it's a dream on the highway. I wish I had a Suregrip rear. :(
On the other hand, my last 72 Corvette had 355 gears from the factory with a 4 speed, and it too was a dream on the highway. The Vette had taller 15" tires though so I suppose that changes things.
I wouldn't be afraid of 355's for the street. They're an awesome gear.

Good Luck with that nice Dart.

George