Trust me...you really want an MK2

I had a 1994 Jeep until a couple years ago. I can't think of a worse environment for an empeg The suspension is like driving a covered wagon.

With that in mind, a couple things you'll want to do: Go ahead and replace the drive immediately with a PATA solid state drive. If you have a MK2 and you are comfortable soldering tiny electronics, go ahead and touch up all the solder joints on the IDE header on the main board, otherwise, I'd advise finding a friend or electronics repair person to do it. In a vehicle that rough, It's probably only a matter of time before the solder joints break and many of them had problems from the factory.

Another problem: I never installed my empeg in my Jeep because I ran with the top off quite a bit, and empegs and water don't mix, but I know of at least one person on here that runs one in their TJ. From experience though, I highly doubt the dash in a YJ is deep enough for it to sit flush in the factory stereo location. The manual says you need 6.8." Also, the empeg doesn't have an internal amplifier, so you'll need an amp of some kind, which usually means a second head unit or an external amp. Finding a spot in a YJ to mount an amp where it will stay dry is challenging. Perhaps a small 4-channel class D amplifier in the glove box or center console will work.

Anyhow, best of luck to you and enjoy your YJ!

EDIT: Another option: I had a Tuffy security console that provided a second secured DIN-sized install location.