I have a 1992 Jeep Cherokee XJ that has had the engine swapped for what I think is a 1995 Cherokee Engine that is the 6 cylinder variant. I have the automatic transmission. I think it is the 3 speed but I am not quite sure. When I got it, it would start but quickly sputter out unless I floored it. I then discovered it had a leaky line from the transmission to the radiator. I then quickly fixed this line with hose clamps and such. I dumped around 1.5 gallons of transmission fluid in and it was able to run and stay running, although in a very rough state. I got it drivable and noticed that past 1500 RPM, the transmission would slip. I added another gallon and now the transmission can get up to around 3000 RPM before slipping. I also notice that when I start the car, it idles very rough for around 5 seconds while in park and then smooths out. When I shift into reverse or forward drive, it idles rough again. Sometimes when I filled the transmission too quickly the overflow valve would let a little fluid out. I let the car sit and then I could keep pouring. I should also note that the transmission was filled while the vehicle was off and then I would run it for a while. At this point it still slips and while the vehicle runs, I don't know if adding more fluid is the solution as I think there is around 3.5 gallons of transmission fluid in the system right now. The more I add the less it seems to slip, but should I keep adding more? Is there a different solution?