Christmas came early

Looks nice, should be a fun project, I'm about to start my big block auto to 4 speed swap. Just wondering, why 3.23's if you have overdrive?
3.23's are what I have currently. Once the car is on the road and I see how it drives I will probably do a swap. Not sure if I will go to 3.55, 3.73, or possibly 4.10 depending on how it drives and cruising rpms.