1.5 auto to 1.8 carb ex

Hi guys,




Just been thinking about how to make my jetta a bit quicker while I save up and collect parts for my 1.8t conversion. 




How easy would it be to put a 1.8 ex carb engine in to replace the 1.5? Would the auto gearbox swap over? What could I use from the 1.5 like inlet etc