best gear ratio for my setup

I run a Ferd 9", and had a 3.89, now 3.7x. I run tall 15" tires which put me at about 32-3300 or so at 70. For the way I drive the car, I love it. A-727 will "do" about 80 in 2nd. Engine has no valve springs, I only turn it 5200 or so, have the limiter on the EFI set to 5.5K