2.93:1 ring and pinion, or complete Sure-grip 742 with same gear ratio

65mph with 26" tires is
2700 with 3.23s
2460 with 2.94s
2310 with 2.76s


For best mpgs at these rpms the cruise-timing will likely want to be over 50 degrees.
You can modify your Vcan to get 22 to 24, leaving 26 to 28 to come from the Initial plus centrifical. Which is easy peasy.
So then, IMO, any of these ratios will be fine for cruising.
But you know, a slanty is gonna be working pretty hard to get up to speed around town, in any case, but more so with the 2.76s, lol. And there goes all the gas-money you saved. The 3.23s are the Go-To for a small-engine dual-purpose car.
The FIRST trick to fuel-economy is to get the ignition-timing dialed in. The closer to optimum you get it, the more closed the throttle can be made to cruise on.
The Factory Distributor is gonna need to be modified no matter which rear gear you choose.