I have a 98 1500 4x2 and a 98 1500 4x4. Can I swap the transmissions or are they not compatible with one coming from a 4x4. The one I need is on the 4x2 as the 4x4 is slipping in the 1st couple of gears. And Im thinking thats why the check engine light is on

 

Nope. Won't work. The O/D housings are different, and swapping the O/D from the blown trans, to the one that works, will only make sure the one that works, stops working in fairly short order.