Automatic conversion

[Johnl48]

I'm doing a complete nut and bolt restoration on a 70 3/4 4x4 with a 350. This is for my wife so she wants it converted to an automatic. She plans on using as a daily driver during the no salt months. I considered the th350 for the simplicity but I fear the gas mileage will prevent her from driving it to work every day

What's everyone's thoughts on the 4L60 with Overdrive ? I know the cross member will need to be moved. Truck has 4.09 gear ratio