need an alternative to granny 4-spd with transfer case

[54chevytruck]

I have a 1954 chevy truck that has parts from many different vehicles in it. As far as i can tell, most of the drive line parts came out of a late 70s early 80s chevy truck(when i had to find a replacement for the brake master cylinder, a 79 chevy one was identical)

Currently it has a granny 4-spd with a transfer case married to the back. from my understanding of it, this transfer case was made to fit only a granny 4-spd.

I need something different. Either a different manual transmission or an automatic.

I just need some suggestions on something that works well that i can replace it with.

Will try to post pictures of it over the weekend