What gears for my build?

[70']

I am I'm neck deep in a frame off to my 70 SWB 4X4, and am weeks away from going through both my differentials. Here is my planned configuration for the rebuild: stock drive train including the Muncie wide ratio 4 speed and stock t-case. Plan to run a 383 stroker. Truck will have a 6" suspension lift and will run 35" mudders. The question is, what gear ratio do I need to run to ensure its not a dog on the bottom end, yet not red lining the tac to go 50 either. Diffs currently have 3:73 gears in them.