Not a A-body but a couple of questions about a 318.

First off 2.94 gears with .73 OD and let's say 29 inch tires. You're only running at about 1600 RPM's at 65 mph, your way out of the power band. You can even cruise in 3rd gear on the freeway at that speed and be at 2200 RPM's.

As said previously 3.55+ gears is a good way to go and it is cheap. You'll definitely will feel it at the seat of your pants.

With 3.55 gears you're at almost 2000 RPM's at 65 MPH at OD.
With 3.73 your at 2050 RPM at 65 at OD
3.91's you going to be at about 2150 at 65 at OD.

Keep in mind this is calculated with 29 inch diameter tires in mind, things can change with different tire sizes.