Changing Gear Ratio in 66 Chevy C30

[kuzco]

Hi,

I'm changing the gear ratio in my 66 Chevy C30 long bed stepside, I also am going to put a 305, 327, 350, or 396 motor in it (haven't decided yet), and a 5 speed transmission, with 17 inch tires on the rear end and 15 inch tires on the front end, it's 2wd, I was curious which gear ratio may be better for my setup, I'd like decent mpg but some power as well (I won't be towing with it) The gears I can choose are:

3.54, 3.73, 4.10, 4.56, 5.11.

Thanks.