If you had a 30 mdl don't put another back in.
Find a 44.
You can find them in CJ 5-7's 72 and up.
You will have to move the spring perches,use wider ones.
The 72-3 will probably have the 3.73 raito but later ones will have higher raitos.
The postal 2 wheel dr will have a 44 that will work
71-75 most with power locks.
Just make sure it's your raito.
Some 68's had 3.31 raito,
You will find this raito in some CJ's.