Final Drive Questions

[Guss]

I am in the planning stages of a crate LS3/trans swap into my 68 stepper. Currently it has 3.73 gears in the rear. At 60 MPH the truck is really winding out. I need recommendations for my final drive ratio based on the following:

1. Freeway cruise speed of 70-75 MPH
2. Economy with some spirit
3. 4L70E top gear ratio of .70-1

On the crate powertrain combo I am considering, (CPSLS3764804L70E) The converter is a lock up with a stall of 3000-3400 RPM. Is this a good stall for a truck that will be my daily driver?

Any help would be really appreciated.

Thanks