2.76 vs 2.94 gearing

It's an entirely stock 68 dart with 273 2bbl and torqueflite. It's a daily driver. I drive it like Ward Cleaver not Mario Andretti. LOL. I do city and freeway driving.
It will be fine, they made many with 2.76. You will need to change speedo gear for it to be accurate.

You will notice it drives different. If you have any hills you will notice them
If you pass on a 2 lane highway it will be more of a dog thatn before.