I just did a 2.5L/AX5 to 4.0/AW4 swap and still working through some problems. I think the biggest problem is the tranny. I wondered if at first it was too full because after the engine heated up and I was heavy on the throttle the ATF would start to leak out between the two pieces of the dipstick tube. Every time I checked the ATF level it seemed plenty full and I was worried it was too full so I decided to drain it this week. I pulled the plug and drained the pan and put in about 3 quarts (just to be safe). Took it for a drive and came back once it was warm to check the level again and it read full even with 3 quarts.
I'm not sure if the ATF isn't cooling enough, if there is an oil resevoir that is clogged or if it is just too full. What do you guys think?