I have a 1999 Ram 1500 ST, 4X4, 5.9L, automatic transmission. My 2nd gear is not working, goes from 1st to 3rd gear. I am thinking of replacing it but can only find 4X2 transmissions. My question is can I swap the extension housing to make a 4X2 transmission a 4X4 transmission and make it work or is there more to it?