Just curious...could one take out the 3.3 V6 and replace it with the 2.4 I4 and still be compatible with 4WD? I know Nissan used to make the Frontier in a 4 cyl. 4WD, was that the same transfer case, transmission, etc. that we have? Was it the same engine that the current 4 cyl Xterras have? I believe it came only in 5-speed manual, so would that make a difference? For instance, could you only swap it with a 5-speed?