If the tranny is in good shape, this could be worth a look. It’s not the 6:1 version.
https://sfbay.craigslist.org/scz/pts/d/santa-cruz-tranny-t18-4spd/7028005844.html
“T-18 4spd 4:1 1st gear. Also has Dana 20 and adapter for Chevy bell housing included”
Is the t-18 a Jeep or ford? Will it fit a 1978 cj5 jeep? Thanks.