Trans Pan

I had the same problem on my 1985 Eagle.

You can get a factory replacement pan from any Jeep dealer, just say it's for the same year Jeep CJ-7. Or you can get it online a little bit cheaper, I bought one from moparpartssource.com and saved a few bucks over dealer price. Note that they asked for the VIN, and in my case at least they insisted that the VIN is not correct for that part. (I convinced them to send it anyway saying I would accept responsibility for the fit. The pan fit perfectly and no more leaks.)

There are aftermarket pans out there but they all tend to be deep, extra-capacity pans which may not fit properly on an Eagle.

I would also definitely get the reusable pan gasket which is also available from Jeep dealers or online. It's got o-rings set in a plastic-covered steel frame. Much easier to deal with than cork or rubber gaskets and you'll never need to buy another one, well worth the price. Just be careful tightening down since it doesn't have the same "give" to it as the old-style gaskets.

This of course assumes you're talking about an automatic transmission.

a 42re pan is deeper than the eagle pan

The 999 is a 32RE in '91 up Wranglers and that's the pan I put on my old Eagle's 998 when I rebuilt it using parts from the 32RE. In hindsight, I could've found a flexplate for the Wrangler and used the TJ case I have and put EFI in my Eagle.