323 355 or 373 gears??

I've got a '62 Valiant with 15-inch wheels, a 408, a 727 and a 3.73 8-3/4". The 3.73 is great for street racing (wait! forget I said that!), but the engine sure does buzz on the freeway. I have a 3.55 in my '77 B200 van, and it doesn't rev up nearly as badly. That's all I can offer, FWIW!