“Best” all around axle ratio: ~450hp w/ A904?

I have GONE from 4.30s to a 3.23 in a similarly powered 65 Valiant. It still pulled like a freight train and the RPMs on the highway were very livable. With the 4.30s I was around 2800 or so. With the 3.23s I went down to around 2200. I never ran the car after the gear change, I sold it shortly after. No doubt it made a difference, but the car still pulled hard. If a car is powerful, it always will be, regardless of gear, you're simply going to "move" where that power can be used.