What options available to change gears in 66 3/4 rear?

[ScottH]

Looking at a 66 3/4 ton truck that I'm pretty sure has 4:57 ratio.
I'd like to change it to 4:10 gear and was wondering what I could use as a donor. Could I swap in a rear from a 72 3/4 4x4 for example? Or what year(s) would be suitable to remove the gears from to install in the original rear?

Any suggestions or info is very much appreciated.

Thanks.

Scott