Im looking to get rid of the 3speed out of my CJ5 and swap in an automatic. What are my options?

What transfer case do you have?
Dana 20: use amc jeep 727 with adapter from a scout with 727 and dana 20 transfercase.
Dana 300: use 727 from 80-89 FSJ wagoneer. use factory FSJ adapter. its same bolt pattern as dana 300. 80-86 CJ7 999s also work.
Make sure you use a flex plate from a 360. 304s and 401s are different part no

I have a TF 727 and Dana 300 out of a 1980 Scout Terra. It was bolted to a International 304. I sent you an email.

Any auto in a CJ5 is going to be pretty long for that short of a wheelbase. Consider length carefully when debating this one.

jeep turbo 400 will bolt to model 20 pretty long but strong and cheap :smokin:

you are going to end up REALLLLLLLY short of the driveline. like a LOT short.
I would also consider moving your rear axle back 3-6 inches at the same time to get some driveshaft length (move the shackle hangers to the end of the frame and weld new front hangers the same distance back you moved the shackle)

But yes a TF727 out of a waggoneer will attach to your engine/t-case but you will need at least 4 inches of lift and maybe a thin diameter front driveshaft in order to clear the transmission. It can get kinda tight for clearance.