transmission help

[Tylerz181500]

im all for having a whole proper gearing, most things ive just acquired knowing and never really understood why its the "proper" gearing.

basically my 72 has 36's 9 inches of lift and a th350-205 and 3.73s ill probably end up taking the body lift off and running 35's or keeping it on and running 35-37's (the 36's are no good)

trucks mostly gonna be a work truck/cruiser, so i dont want to be too high up in the rpm range if i have to go on the highway, so my thoughts were either what rear end gears would i need? id like to go to a 14 bolt/60/70 or an eaton if i can, or should i swap to a 4l80e-205 so i an have overdrive?

i havent gotten into looking at 4l80e swaps yet